I so love your writing. You may not remember me but, I'm the guy who quote your writing in your episode, _Pulling Energy Out of Thin Air_ _Without a difference in thermal states from which to establish a flow of energy ..._ _No mechanical work can be extracted from the system. (talk about elegant writing)_ Or ... the full snippet: The 1st law of Thermodynamics dictates: Entropy of an isolated system, left to evolve naturally, can never decrease ... and will always arrive at a state of thermodynamic equilibrium in which, entropy reaches its maxim. Without a difference in thermal states from which to establish a flow of energy, no mechanical work can be extracted from the system. In effect, as entropy increases, the amount of energy that can be extracted decreases. This inherent natural progression of entropy towards Thermal-Equilibrium ... directly contradicts the behavior of all perpetual-motion-machines of the second kind. SUCH beautiful writing; even hearing the second time is still stunning. I hope people don't confuse this extraordinary level of clarity nor the simplicity with which he reduces these complex concepts ... for being "easy." Those who do have really missed out on the joys of edification. But something tells me, those who've found this true gem of youtube ... know, this simply is not the quality of language heard in one's daily life.
Not meant to dis Brilliant in any way being the proud sponsor of this, as well as many of your wonderful videos... but it might have been a humoring twist to have "Henson Shaving", or those Chinese made *"Japanese Kitchen Knives"* promos for this one.
3:00 “…..superior to ANY stone blades”…….. hmmmm. Interesting and yet obsidian surgical blade/knives; a so called “stone age technology”still finds a place amongst present day surgeons.
Science and history go hand in hand. If the two being interlinked wasn’t deemed important, we would not be bothering with associating scientific principles, math, or technology with people, civilizations, and eras.
What I expected when i clicked the video titled "The Science of Cutting": the Science of Cutting. Like Mohs scale, tool hardening, shear forces and other factors involved in cutting I'm not even aware of. What i did not expected: Brief history of metallurgy and machine tools development Was i disappointed? Hell no. I still learned a ton of details in the areas I thought I had descent familiarity with.
Same expectation, different reaction. Didn’t get the science of cutting so I skipped and skipped, until I realised the whole thing was a history lesson.
agreed. due to the thumbnail, i expected something more along the lines of butchering meat, cutting, trimming.. not that i mind the history lesson...albeit brief, was just not what i was expecting.
Almost all other videos of new mind are super specific, with tons of new information. I was indeed a little bit dissapointed. It´s still one of the better engineering channels here on youtube. Keep up the good worl!
Bronze is insanely resistant to corrosion. In fact that’s probably why there are still artifacts available today. Bronze is still the preferred metal for use in salt water environments
Yea, in fact steel rusts, and the rust doesn't protect the metal. When bronze corrodes, the corrosion product forms a layer that stops further corrosion, meaning they can last nearly forever, it's why you can find elemental copper out in the wild, and why you never find elemental iron out in the wild (unless it's meteoric iron). In the old testament it talks about someone becoming upset losing an iron axe head (this was in the bronze age, meaning any iron tool was insanely expensive), and through prayer was able to recover it. Iron/steel tools proved to be vastly superior, but it remains that they do rust. They only last when we actively protect them, or polish them regularly and oil them.
@@taiwanluthiersYes. Also, interestingly, the fact that iron rusts isn’t technically the issue. All metals corrode in some way and in difference circumstances. But the problem with iron corrosion like red oxide (as opposed to black oxide) is that the resulting size of the material that forms is physically larger than the parent material. It as it grows it must flake and fall off exposing new metal to corrode again and so on and so forth until there’s nothing left. So it’s not that iron corrodes is the issue, it’s that as it corrodes it falls off and re corrodes.
@@taiwanluthierswow, upset equals to insanely expensive? Your comment was interesting until I got there. Is this how you religious people form conclusions?
birds, whales, alligators, turtles, and many more animals do that as well. it is not a human invention to pass information down between generations. but I understood your point.
This. Once we started writing things down and compressing someone's life's work into a book that can be read in a few weeks and expanded upon it was game on
I had just wrote something about our unique ability to release and use stored energy. Even though some animals (such as Orka) teach their young and even have culture, you're right. Absolutely right.
Machinist are a dying breed, with good reason. As a machinist I make two dollars an hour more than a "sandwich artist" at Subway. You know how depressing that is. I can hold parts to one ten thousandths of an inch both manually and on cnc. I have to buy thousands of dollars of my own tools to do the job, risk serious injury and death just moving the giant metal parts around, not to mention actually running the parts in the machines. The whole reason I make so little is because some poor man in sandals from India or China is willing to do what I do under way worse conditions for two dollars an hour and nobody in the West gives a fuck about him as long as they get cheap shit... And that is what is wrong with the world today.
Boils down to what my agriculture teacher always preached in high school. "It's a throw away world". No one cares when you can go buy another piece of crap for couple dollars. He beat it into us to at least sharpen our own screwdrivers if we had quality screw drivers to start with. And to further manufacture and rebuild anything we could for ourselves.
it is wrong to blame poor men in sandals from India or China for your low wage. your wages are fixed by local policies made by local governments or financial bodies in association with local companies. you should rather thank poor workers in India or China for your clothes or shoes or perhaps your underwear - just imagine your clothes being stitched in New York with workers getting paid like state cops! if you want to know more, just find out the terrible conditions (and pays) the garment workers in south asian countries works.
@janami-dharmam that's exactly why we SHOULDN'T be manufacturing in those countries. People want cheap crap and it isn't good or healthy for us or them. Also if we were manufacturing here it wouldn't be as expensive.
The title of the video is covered in the first 2 minutes. Then expect a history lesson on metals and technology advancements of computers. I hit pause at 14minutes and thought to myself what then hell am I watching? There's nothing in the majority of this video about cutting, nothing at all about blade design or evolution of a blade. The only thing at this point related to actual cutting is the mention of what is rotating, the cutting tool or the object being cut. Along with how precise a cut can be made, but no mention of how that precision is achieved by a blade. But for some reason I was told what the first billion dollar company was. Why a steel manufacture needs that shout out in a video about cutting, I'm not sure. I assumed blade manufactures would have been getting the shout out. But they are ignored. I'm at 14 minutes a little past half way and couldn't tell you the science of blade design. Why some blades are flat on one side and others are angled on both sides? No clue. The angle of blade has anything to do with cutting? No clue. The actual shape of a cutting edge or how to properly sharpen a cutting edge, no clue. I started to question the video when I saw a refinery displayed while it talked about steel mills. LoL two drastically different shaped facilities and products confused. Detailed information is provided about metal alloys but not how that relates to a cutting edge along with the evolution of the lathe is provided, but no mention is given to the evolution of the cutting tools used. Just the machine itself, missing the whole point of the video
1:10 Why whenever they depict early humans they are always waddling around and super uncoordinated. These people were strong and athletic and were way more sure footed and aware of their bodies than we are today, probably. It’s not like they were all hunched over Quasimodos barely surviving on beetles with dirty faces and leaves in their hair. They were a healthy, strong, fully fledged species that survived for thousands of years.
metallurgy needed prospecting for the ore and fuel. Charcoal rather than coal was common. furnace was a real high tech device. controlling fire and temperature and smelting of ores need cooperative efforts.
Even wild animals groom themselves.You will never see a wild ape or other animal with as matted or unkempt fur as a typical barbarian or caveman depiction. Tribal people have all their decorations just as is the tradition of the tribe. Scruffy people are an urban civilised phenomenon
Modern humans have a superiority complex that is off the scale. Most people think they are better than the other bloke. Better workers, better drivers, more intelligent, etc. It follows that we think of our forefathers as being less capable than ourselves. But this is not true. No caveman ever wore rough animal hides with bits dangling off it. Any man who could skin an animal and process the hide into soft leather was well capable of tailoring it onto fitted clothing. Stone age man would often take a break and produce artistic items out of a desire to make his belongings more beautiful. They were much better than we like to admit. They were simply lacking technology that was not yet invented.
@@anordenaryman.7057 just like we think white skin is better than dark skin, if an American girl hangs two meatballs from her two ears we go gaga over that... but it is too easy to criticize. one 7000 year old mummy was found it Italy (Otzi the Iceman) - he had an incredibly nice shoe! Adidas may take note!!
Because early humans were breaching the gap between ape and human, you’re thinking of the generation after, that developed perfect upright walking like we do today.
@@Mastermindyoung14 They won't hold up in consistent seawater service. I work in shipbuilding; use AlBrz an NiAlBrz quite frequently, but for stuff that really needs to hold up to seawater it's cupronickel, Monel and K-Monel, Inconel 625, and occasionally Gr 2 Ti.
There's more than few inaccuracies here (and mismatched video clips), but that _"[it] blew oxygen through the molten metal"_ was that proverbial last straw. No, back then they blew AIR through molten pig iron, and the oxygen contained in AIR did the job. "Basic oxygen steel making" came much, much later: _The basic oxygen process developed outside of the traditional "big steel" environment. It was developed and refined by a single man, Swiss engineer Robert Durrer, and commercialized by two small steel companies in allied-occupied Austria, which had not yet recovered from the destruction of World War II_ _In 1856, Henry Bessemer _*_had patented_*_ a steelmaking process involving oxygen blowing for decarbonizing molten iron (...). For nearly 100 years commercial quantities of oxygen were not available or were too expensive, _*_and steelmaking used air blowing*. During WWII German (Karl Valerian Schwarz), Belgian (John Miles) and Swiss (Durrer and Heinrich Heilbrugge) engineers *proposed_*_ their versions of oxygen-blown steelmaking, but only Durrer and Heilbrugge brought it to mass-scale production_ ...and it happened only in 1948: _In 1943, Durrer ... returned to Switzerland ... . In 1947 he purchased the first small 2.5-ton experimental converter from the US, and on April 3, 1948 the new converter produced its first steel ... In the summer of 1948, Roll AG and two Austrian state-owned companies, VÖEST and ÖAMG, agreed to commercialize the Durrer process_ Hey, that's Wiki. No need for any in-depth and time consuming research, just basic fact-checking
@@chrissorensen9511 ...and some has to do it. Still, I'd rather say that "nitpicking" is when we watch a silly hollywoody utter fiction movie, with, say, a black Cleopatra in it, and then we nitpick on some tertiary details like "the swords they were using in this or that scene came to existence only a century latter", and when someone points out factual inaccuracies in a supposedly pop-science video, he is pointing out inaccuracies, not "knocking" or "nitpicking". Or so I think.
Sharp sticks. See if you fire harden the point, a smart human can make pointy sticks that can take on bears/lions/etc. A group of people with pointy sticks to protect themselves will be safe from those predators. Or if people want to, then can become the top predator!
This is a new one on me ! You can actually make the point of a stick harder with fire ? Does it give up any sharpness ? A harder tip might be worth a little trade off ?
As the lead mechanical design engineer for a large tech company, this video gets me GOING. On the machine screw level I can tell threads by eye. What amazing history lead to what I use. I can take surface to edge angle / distance, plane to plane measurements and validate fasteners for use with a couple clicks using CAD. What a time to be alive :)
Fortunately, I lived through these changes. Truly incredible progress has been made with the entry of computer technology into this profession. I started CNC programming on a small EMCO cutting machine. Today, knowledge of PLC codes is not required in many places. We sharpened the tools while holding them in our hands, now machines do this for us as well. I'm programming sharpening machines like this now. :) :)
The material science of cutting It would be cool to see a video like this about blade and cutting tool geometries. The shape of cutting tools varies wildly between tools of the same material
This would mean a depth of this profession that would provide enough material for many, many videos. But there are such channels. Specifically, even my language (Hungarian) has 3. I have been engaged in machine cutting since 1984, sharpening tools since 1997.
My grandfather was a toolroom machinist in a paper mill, my dad had started as a machinist in the Navy and went on to design paper bag machinery. I once found a small sculpture of an eagle that my cousin had made. At dinner one night I (probably around ten at the time) marveled at how he had carved that eagle out of aluminum with an X-Acto knife; until then I had no idea that cutting something as hard as metal was possible. My dad responded, "What do you think we do all day?" Years later I came up with the snappy reply, "How would I know? You never talk about it." I guess this story has more to do with family dynamics than cutting technology. I went on to become a machinist and tooling designer myself, BTW.
I think you could have gone more into the details of the shapes, angles and hardness of blades and cutting elements. Still, this is a very good summary of tooling technology advancement.
one of the things that solidified how cutting metals worked for me was using a cold cut saw (not the meat) which had a carbide toothed blade about a quarter inch thick. it spun slow with coolant and was a beast of a machine. It was loud as hell too, so I didn't want to go too rough on it but my boss said I was wasting money not being aggressive with the saw since technically it's taking less cuts and wears the teeth out less.
10 of of 10 presentation. Teaching and the history of sharp strong cutting tools. As a ex-Butcher the knife blade edge was very important.,if the blade edge was to sharp eg 11 degrees the knife would become blunt very quickly,if the edge was 25 degrees or more it would make for hard work boning and cutting. Between 20-22 degrees was just right. We were told at college that you never cut yourself with a sharp knife.the blade cuts and flows in the direction you are cutting but a blunt knife has to be forced and can result in changing direction with potential to cut you.growing up in the trade a man at a butcher shop near me was boning a beef chuck and the knife slipped and went straight into his thigh,he died right there were he was working.😢 Thank you 👍🏼 Australia
I teach engineering students in a machine shop. You have just added content to my mill and lathe classes. You WILL be credited and I will steer students to this video for a deeper dive. Well done.
613k subscribers, and sponsored. Not sure about underrated lol. Either way it's good introduction to the basics of material properties in regards to cutting. Good stuff
As someone watching this video while also operating a CNC machine, I feel honored and thankful for everyone involved in getting us here. I wouldn’t have this job without them.
Great video, thanks. As a highly skilled mashinist, it warms my heart to watch this. But a slight correction; it was not Watt the boring mashine was made for, but Thomas Newcomben. Originaly made to bore out canonbarrels. And it was only made possible by Darbys use of coke to melt iron, not charcoal. Otherwise enough iron could not be made, to cast a cylinder.
@@enja001 Yes, exactly. Darby made his melt in 1709, and Newcomben made his engine in 1712. The reason it was an atmospheric engine and not a steamengine was, the tecnologi was not good enough to make a boiler able to withstand the pressiore. The rivet was not invented yet.
I poured Grey and Ductile Iron at Sather Manufacturing in Everett Washington State for good old Jody 😅 ahww awww and I loved it. I was doing Shakeout. We clamped molds for about an hour and we tapped out. We would pour from a Ladle weighing 1000# and carrying 3000# of bright orange almost yellow molten Iron and poured the molds we just clamped. After doing 9 Heats the first poured Castings were cool enough to shake out and not warp. We put them in the next room over with a power overhead crane. I started work at 11 am and didn't get to go home until All the molds we poured we're shook out and the sand shoved in the corner of the shop to be used to make tomorrow's molds. With a Bobcat Skid Steer 😏 I had so much fun and blasting a manhole cover hanging from the chain and knock off the sand with sludge hammer's was the highlight 🙂❣️🇺🇲🖖 9:04
Fascinating! At 21:30 there is an impeller being CNC machined. Do I recall correctly that this is a Space Shuttle part and is thought to be among the most complex parts ever to have been machined? Do you have references to this particular process?
You are making me psychotic man! Every interest I pursue, either leads to one of your old videos, or you upload one while i'm pursuing it. And always being the highest quality. I'm glad I stuck around since the beginning of this channel!
11:32 "...could cut a 1m bore to an accuracy of 1.5..." my machinist brain thinks 1.5 thousands of an inch? 1.5 microns??? "...millimeters." Actually lol'd at that. Its crazy how quickly our machine tools advanced in accuracy and precision
Open hearth furnaces were NOT more efficient than Bessemer converters but they did not introduce nitrogen into the steel like blowing air through it. Without nitrogen open hearth steel was much tougher especially at lower temperatures. We operated 1400 ton open hearths in the mid 1960s. Open hearths were replaced by basic oxygen furnaces - similar to Bessemer converters except blown with pure oxygen rather than air. The pictures of dislocations was interesting, especially with them moving. You need to do more research on the history of metallurgy. I'd recommend "making, shaping and treating of steel" as one source. Later bronze swords were better than the early iron swords but iron was much cheaper so a noble could arm more soldiers. Adding Be to copper or bronze can increase the hardness to Rockwell C 45. Egyptians knew this.
I have a gigantic 3D printed CNC i desgined, so this was fun to watch 🙃 i can cut wood, plastics, aluminum, brass, amd copper. Its really cool to see how far we have come and how fast we are moving.
This video is reminds me of having to do an essay in school on a topic with no real information, so you kinda end up writing about something that is only slightly relevant to get enough words for the quota
Thank you so much for all your hard work making this video. Truly high quality content. 15 years ago the only place to learn anything like this was at university. Just amazing what I am able to learn in the comfort of my own house.
Excellent video, I learned a lot. Just wanted to point out that the reason why the discovery of the basic Bessemer process (using alkaline minerals for refractory lining) cut costs so much. As you said it allowed for the use of phosphorous-containing iron ores in steel-making. Phosphorous is a very common contaminant in iron deposits, and thus most deposits were unavailable for exploitation because the phosphorous contaminant would have rendered the steel brittle and useless. The cost of steel dropped when we no longer had to mine phosphorous-free ore (which often also has low iron content).
I was so enamored by the history of metal alloys that I forgot this video was about cutting until about the 10:40 mark. Great video. I'd love to see a game that incorporates such a granular progressions through metallurgy. Going from stone tools to copper to bronze to iron to pig iron to cast iron to steel to high speed steel.
Maybe not what you'd expect, but LOTRO has a system like that. From mining the ores, to smelting them with coals and such, to mixing the metals and making armours, tools, weapons etc.
@@tectzas Yeah, besides me being a Middel Earth fan, that crafting system is a good chunk of why I like the game haha. You can check the LOTRO wiki to read all about how the crafting system works.
Would love to see a more in-depth history of the beginnings of metallurgy. Most certanly wasn't there one person who on day said "let's build a furnace, mix copper and zinc and create bronze". How did people come up with melting stones, so metal would come out of them? How did they discover the different properties of different metals and how did they manage to mix (alloy) them so they'd enhance each other properties thousands of years before chemistry became an actual science with methodical proceses?
Not what I expected, but still enjoyed. Was expecting to see how manufacturers develop cutters for different materials and situations such as interrupted cuts or hard metals.
As a tool sharpener, I can say that in most cases the exact definitions fall into the category of industrial secrets. Of course, some values can be determined superficially, but today we make unique tools for specific material quality and specific work. Cutting is thus much more efficient. But he also mentioned coatings superficially, as well as outdated information. In ~5 years, the efficiency of the coatings was increased by >30%.
5:40 I once put a 5cm stripped copper wire into a drill and the other end into a vice, after roughly 250 turns it broke clean at the drill. When I analyzed it, it was almost as hard as a steel nail, but would break when under too much load.
From my understanding, limestone was used in blast furnaces since ancient times although the reason (i.e. the exact chemical processes) were unknown, people just knew limestone created removable slag that improved the final iron product. The other things you mentioned did greatly reduce the cost of steel production in the late 1800's, though, such as the Bessemer Process and the Oxygen Process, and others not mentioned (e.g. Siemens-Martin regenerative preheating). Still, excellent video, very high quality and production level!
I learned a few things! Great YT vid. One thing I have to say is that for the last 40 years people have said that the U.S. doesn't manufacture anything. We make the finest, and most expensive machine tools known to man. They ain't cheap. China sends more material and goods to us, by volume/mass. We send the most advanced and best equipment the other way. By cost/value? We export more than we import. Same with India/Egypt/Brazil... what have you.
7:50 seems a bit f confusion here puddling furnaces turn high carbon cast iron into low carbon wrought iron. Cast iron is produced by the blast furnace.
it is improper to say cutting shear force. any cutting has to start with high crushing stress otherwise the sharpness of the tool becomes unimportant. if only shear stress is important to cut, one can cut with blunt tool (other edge than sharp edge).
Congratulations. Wonderful content. You've just made a nice and gentle summary of machining, with details that I wasn't anticipated when I saw the video title… There are some statements that would lead to misinterpretations, like the bronze oxidation, but the overall content is remarkable.
I have been watching your channel since the science of roundness and I always forget exactly how good your videos can be! lmao. When I clicked on this I did not expect an overview of this depth of the topics covered in both my materials and manufacturing classes in uni. Have you tried targeting the struggling mech E students yet?? A ton of students use youtube for help with course work/material and I do wonder how you would approach a video dedicated to material in a college level course. (like heat transfer or applied thermo). Love these vids! This, flatness, roundness, of course the more ME focused vids have been my favorite so far.
Some animals have various cutting capabilities, and animals even use tools. But what differentiates human from other animals is our ability to use stared energy. Stored energy, such as fuels for burning like wood and oil helped keep us warm, cooking food (making it more edible), and do metal work.
As far as I know, glass (man-made and obsidian) can make much more sharp edges than any metal. Metals are more resistant to alternating load and breaking, of course.
The machine that makes a machine tool different from any other is the use of the screw to precisely control the application of the cutting edge to the work. It's really that and not the application of power. A power tool isn't necessarily a machine tool. A machine tool can be human powered and still be a machine tool. If you have to turn a wheel to make a cut happen, it's a machine tool. If you have to push to directly move an edge to make a cut happen, it isn't. It's that the cut is constrained, guided by a way, and fed by a screw or lever (which themselves are basic machines) which makes a machine tool such. A woodworking lathe where you apply a chisel you hold in your hand to a spinning workpiece isn't a machine tool, but it is a power tool. An electric drill you aim by hand also isn't a machine tool, neither is a router you aim and move about by hand. A screw cutting lathe is, a mill is, even a pedestal drill is (although barely, because it has a quill you lower by turning a wheel). CNC machines of course all must be, but so too must the 'power feed' axies which a mill or lathe might have. But it seems too often people equate 'machine' with 'has power from other than a human', and it just isn't so. A lever is a machine, so is a ramp or wedge, and the latter wrapped around a rod makes a screw thread, which is really just a fancy inclined plane which allows rotation to make controlled linear motion along the rod. That being used to change the position of a cutting tool, whilst another axis spins it, is what a screw-turning (metalworking) lathe is. It's not the spinning-ness of the work - it's the controlled positioning of the cutting edge.
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I so love your writing. You may not remember me but, I'm the guy who quote your writing in your episode, _Pulling Energy Out of Thin Air_
_Without a difference in thermal states from which to establish a flow of energy ..._
_No mechanical work can be extracted from the system. (talk about elegant writing)_
Or ... the full snippet:
The 1st law of Thermodynamics dictates: Entropy of an isolated system, left to evolve naturally, can never decrease ... and will always arrive at a state of thermodynamic equilibrium in which, entropy reaches its maxim. Without a difference in thermal states from which to establish a flow of energy, no mechanical work can be extracted from the system. In effect, as entropy increases, the amount of energy that can be extracted decreases. This inherent natural progression of entropy towards Thermal-Equilibrium ... directly contradicts the behavior of all perpetual-motion-machines of the second kind.
SUCH beautiful writing; even hearing the second time is still stunning. I hope people don't confuse this extraordinary level of clarity nor the simplicity with which he reduces these complex concepts ... for being "easy." Those who do have really missed out on the joys of edification. But something tells me, those who've found this true gem of youtube ... know, this simply is not the quality of language heard in one's daily life.
Not meant to dis Brilliant in any way being the proud sponsor of this, as well as many of your wonderful videos... but it might have been a humoring twist to have "Henson Shaving", or those Chinese made *"Japanese Kitchen Knives"* promos for this one.
3:00 “…..superior to ANY stone blades”…….. hmmmm. Interesting and yet obsidian surgical blade/knives; a so called “stone age technology”still finds a place amongst present day surgeons.
Tanum carbide. I wonder of thats a tantalum alloy.
No
misleading title, should be "The history of cutting tools"
Agreed. But it's such a good video.
Sigh, no science noted.
Science and history go hand in hand. If the two being interlinked wasn’t deemed important, we would not be bothering with associating scientific principles, math, or technology with people, civilizations, and eras.
@@patrickguyumagree, 99.99% of science is historical
1:13 - 2:09
What I expected when i clicked the video titled "The Science of Cutting": the Science of Cutting. Like Mohs scale, tool hardening, shear forces and other factors involved in cutting I'm not even aware of.
What i did not expected: Brief history of metallurgy and machine tools development
Was i disappointed? Hell no. I still learned a ton of details in the areas I thought I had descent familiarity with.
Same expectation, different reaction. Didn’t get the science of cutting so I skipped and skipped, until I realised the whole thing was a history lesson.
agreed. due to the thumbnail, i expected something more along the lines of butchering meat, cutting, trimming.. not that i mind the history lesson...albeit brief, was just not what i was expecting.
Almost all other videos of new mind are super specific, with tons of new information. I was indeed a little bit dissapointed. It´s still one of the better engineering channels here on youtube. Keep up the good worl!
Me too.
Yeah was hoping for science not history. It was still interesting and enjoyable.
Bronze is insanely resistant to corrosion. In fact that’s probably why there are still artifacts available today. Bronze is still the preferred metal for use in salt water environments
Yea, in fact steel rusts, and the rust doesn't protect the metal. When bronze corrodes, the corrosion product forms a layer that stops further corrosion, meaning they can last nearly forever, it's why you can find elemental copper out in the wild, and why you never find elemental iron out in the wild (unless it's meteoric iron). In the old testament it talks about someone becoming upset losing an iron axe head (this was in the bronze age, meaning any iron tool was insanely expensive), and through prayer was able to recover it. Iron/steel tools proved to be vastly superior, but it remains that they do rust. They only last when we actively protect them, or polish them regularly and oil them.
@@taiwanluthiersYes. Also, interestingly, the fact that iron rusts isn’t technically the issue. All metals corrode in some way and in difference circumstances. But the problem with iron corrosion like red oxide (as opposed to black oxide) is that the resulting size of the material that forms is physically larger than the parent material. It as it grows it must flake and fall off exposing new metal to corrode again and so on and so forth until there’s nothing left. So it’s not that iron corrodes is the issue, it’s that as it corrodes it falls off and re corrodes.
nice, someone realized that weird statement
@@c0mputerRust jacking is a real thing.
It's almost as powerful as ice expanding, which is really saying something!
@@taiwanluthierswow, upset equals to insanely expensive? Your comment was interesting until I got there. Is this how you religious people form conclusions?
Humanity's greatest achievement is passing down information through generations
Yeah and eventually one of those generations inevitably and utterly fucks it up with their bad ideas to tac on.
@@UtubeH8trlike the monetization and gate keeping of information
birds, whales, alligators, turtles, and many more animals do that as well. it is not a human invention to pass information down between generations. but I understood your point.
This. Once we started writing things down and compressing someone's life's work into a book that can be read in a few weeks and expanded upon it was game on
I had just wrote something about our unique ability to release and use stored energy.
Even though some animals (such as Orka) teach their young and even have culture, you're right. Absolutely right.
Machinist are a dying breed, with good reason. As a machinist I make two dollars an hour more than a "sandwich artist" at Subway. You know how depressing that is. I can hold parts to one ten thousandths of an inch both manually and on cnc. I have to buy thousands of dollars of my own tools to do the job, risk serious injury and death just moving the giant metal parts around, not to mention actually running the parts in the machines. The whole reason I make so little is because some poor man in sandals from India or China is willing to do what I do under way worse conditions for two dollars an hour and nobody in the West gives a fuck about him as long as they get cheap shit... And that is what is wrong with the world today.
Boils down to what my agriculture teacher always preached in high school. "It's a throw away world". No one cares when you can go buy another piece of crap for couple dollars.
He beat it into us to at least sharpen our own screwdrivers if we had quality screw drivers to start with. And to further manufacture and rebuild anything we could for ourselves.
it is wrong to blame poor men in sandals from India or China for your low wage. your wages are fixed by local policies made by local governments or financial bodies in association with local companies. you should rather thank poor workers in India or China for your clothes or shoes or perhaps your underwear - just imagine your clothes being stitched in New York with workers getting paid like state cops! if you want to know more, just find out the terrible conditions (and pays) the garment workers in south asian countries works.
Big facts. Struggling for a similar reason.
@janami-dharmam that's exactly why we SHOULDN'T be manufacturing in those countries. People want cheap crap and it isn't good or healthy for us or them. Also if we were manufacturing here it wouldn't be as expensive.
@@janami-dharmam I didn't mean poor in a monetary sense and the sandals were a references to the unsafe conditions they work in.
The title of the video is covered in the first 2 minutes. Then expect a history lesson on metals and technology advancements of computers. I hit pause at 14minutes and thought to myself what then hell am I watching? There's nothing in the majority of this video about cutting, nothing at all about blade design or evolution of a blade. The only thing at this point related to actual cutting is the mention of what is rotating, the cutting tool or the object being cut. Along with how precise a cut can be made, but no mention of how that precision is achieved by a blade. But for some reason I was told what the first billion dollar company was. Why a steel manufacture needs that shout out in a video about cutting, I'm not sure. I assumed blade manufactures would have been getting the shout out. But they are ignored. I'm at 14 minutes a little past half way and couldn't tell you the science of blade design. Why some blades are flat on one side and others are angled on both sides? No clue. The angle of blade has anything to do with cutting? No clue. The actual shape of a cutting edge or how to properly sharpen a cutting edge, no clue. I started to question the video when I saw a refinery displayed while it talked about steel mills. LoL two drastically different shaped facilities and products confused. Detailed information is provided about metal alloys but not how that relates to a cutting edge along with the evolution of the lathe is provided, but no mention is given to the evolution of the cutting tools used. Just the machine itself, missing the whole point of the video
thanks I think i'll just leave now
All of this is because youtube removed the unlike button...sort of.
@KUSHALGOKHALE it needs an unlike button for the title. Or a flag option for misleading titles.
Agree the title is wrong. I still enjoyed the video.
“The advancements in the technology of cutting” could be a better title perhaps.
1:10 Why whenever they depict early humans they are always waddling around and super uncoordinated. These people were strong and athletic and were way more sure footed and aware of their bodies than we are today, probably. It’s not like they were all hunched over Quasimodos barely surviving on beetles with dirty faces and leaves in their hair. They were a healthy, strong, fully fledged species that survived for thousands of years.
metallurgy needed prospecting for the ore and fuel. Charcoal rather than coal was common. furnace was a real high tech device. controlling fire and temperature and smelting of ores need cooperative efforts.
Even wild animals groom themselves.You will never see a wild ape or other animal with as matted or unkempt fur as a typical barbarian or caveman depiction. Tribal people have all their decorations just as is the tradition of the tribe. Scruffy people are an urban civilised phenomenon
Modern humans have a superiority complex that is off the scale. Most people think they are better than the other bloke. Better workers, better drivers, more intelligent, etc. It follows that we think of our forefathers as being less capable than ourselves. But this is not true. No caveman ever wore rough animal hides with bits dangling off it. Any man who could skin an animal and process the hide into soft leather was well capable of tailoring it onto fitted clothing. Stone age man would often take a break and produce artistic items out of a desire to make his belongings more beautiful. They were much better than we like to admit. They were simply lacking technology that was not yet invented.
@@anordenaryman.7057 just like we think white skin is better than dark skin, if an American girl hangs two meatballs from her two ears we go gaga over that...
but it is too easy to criticize. one 7000 year old mummy was found it Italy (Otzi the Iceman) - he had an incredibly nice shoe! Adidas may take note!!
Because early humans were breaching the gap between ape and human, you’re thinking of the generation after, that developed perfect upright walking like we do today.
Bronze and aluminum bronze is still the king for many maritime machinery components. INCREDIBLE corrosion resistance
LC200n, H1/2, and a few other steels are essentially "rust proof"
@@Mastermindyoung14 They won't hold up in consistent seawater service.
I work in shipbuilding; use AlBrz an NiAlBrz quite frequently, but for stuff that really needs to hold up to seawater it's cupronickel, Monel and K-Monel, Inconel 625, and occasionally Gr 2 Ti.
There's more than few inaccuracies here (and mismatched video clips), but that _"[it] blew oxygen through the molten metal"_ was that proverbial last straw. No, back then they blew AIR through molten pig iron, and the oxygen contained in AIR did the job.
"Basic oxygen steel making" came much, much later:
_The basic oxygen process developed outside of the traditional "big steel" environment. It was developed and refined by a single man, Swiss engineer Robert Durrer, and commercialized by two small steel companies in allied-occupied Austria, which had not yet recovered from the destruction of World War II_
_In 1856, Henry Bessemer _*_had patented_*_ a steelmaking process involving oxygen blowing for decarbonizing molten iron (...). For nearly 100 years commercial quantities of oxygen were not available or were too expensive, _*_and steelmaking used air blowing*. During WWII German (Karl Valerian Schwarz), Belgian (John Miles) and Swiss (Durrer and Heinrich Heilbrugge) engineers *proposed_*_ their versions of oxygen-blown steelmaking, but only Durrer and Heilbrugge brought it to mass-scale production_
...and it happened only in 1948:
_In 1943, Durrer ... returned to Switzerland ... . In 1947 he purchased the first small 2.5-ton experimental converter from the US, and on April 3, 1948 the new converter produced its first steel ... In the summer of 1948, Roll AG and two Austrian state-owned companies, VÖEST and ÖAMG, agreed to commercialize the Durrer process_
Hey, that's Wiki. No need for any in-depth and time consuming research, just basic fact-checking
Lame
@@josephfcarrillo Hello, Lame, nice to meet you... Nah, just kidding ;-)
Sometimes, nits must be picked.
@@chrissorensen9511 ...and some has to do it.
Still, I'd rather say that "nitpicking" is when we watch a silly hollywoody utter fiction movie, with, say, a black Cleopatra in it, and then we nitpick on some tertiary details like "the swords they were using in this or that scene came to existence only a century latter", and when someone points out factual inaccuracies in a supposedly pop-science video, he is pointing out inaccuracies, not "knocking" or "nitpicking".
Or so I think.
This is what happens when you get chatgpt to write your script
This wasn't really the science of cutting. It was the science of metallurgy
The history of metallurgy.
The title is simply a lie.
Thumbs down and block.
@@CalvinHikes block? lol
Sharp rocks are probably our #3 all time invention.
#1 being heavy rocks for hitting things and #2 being fire.
Sharp sticks. See if you fire harden the point, a smart human can make pointy sticks that can take on bears/lions/etc. A group of people with pointy sticks to protect themselves will be safe from those predators. Or if people want to, then can become the top predator!
This is a new one on me ! You can actually make the point of a stick harder with fire ? Does it give up any sharpness ? A harder tip might be worth a little trade off ?
What about the wheel?
I thimk the wheel needs a place
no wheel or string??
As the lead mechanical design engineer for a large tech company, this video gets me GOING.
On the machine screw level I can tell threads by eye. What amazing history lead to what I use. I can take surface to edge angle / distance, plane to plane measurements and validate fasteners for use with a couple clicks using CAD.
What a time to be alive :)
Fortunately, I lived through these changes. Truly incredible progress has been made with the entry of computer technology into this profession. I started CNC programming on a small EMCO cutting machine. Today, knowledge of PLC codes is not required in many places.
We sharpened the tools while holding them in our hands, now machines do this for us as well. I'm programming sharpening machines like this now. :) :)
The material science of cutting
It would be cool to see a video like this about blade and cutting tool geometries. The shape of cutting tools varies wildly between tools of the same material
This would mean a depth of this profession that would provide enough material for many, many videos. But there are such channels. Specifically, even my language (Hungarian) has 3.
I have been engaged in machine cutting since 1984, sharpening tools since 1997.
My grandfather was a toolroom machinist in a paper mill, my dad had started as a machinist in the Navy and went on to design paper bag machinery. I once found a small sculpture of an eagle that my cousin had made. At dinner one night I (probably around ten at the time) marveled at how he had carved that eagle out of aluminum with an X-Acto knife; until then I had no idea that cutting something as hard as metal was possible. My dad responded, "What do you think we do all day?" Years later I came up with the snappy reply, "How would I know? You never talk about it." I guess this story has more to do with family dynamics than cutting technology. I went on to become a machinist and tooling designer myself, BTW.
You can't cut aluminum with an exacto knife so what do you mean?
I think you could have gone more into the details of the shapes, angles and hardness of blades and cutting elements.
Still, this is a very good summary of tooling technology advancement.
The Bessemer process was invented (and first used) in my city!! :D (Sheffield, UK)
Stainless was also invented here :)
as well as Crucible steel!
Spot on. Lets get the history right.
one of the things that solidified how cutting metals worked for me was using a cold cut saw (not the meat) which had a carbide toothed blade about a quarter inch thick. it spun slow with coolant and was a beast of a machine. It was loud as hell too, so I didn't want to go too rough on it but my boss said I was wasting money not being aggressive with the saw since technically it's taking less cuts and wears the teeth out less.
10 of of 10 presentation.
Teaching and the history of sharp strong cutting tools.
As a ex-Butcher the knife blade edge was very important.,if the blade edge was to sharp
eg 11 degrees the knife would become blunt very quickly,if the edge was 25 degrees or more it would make for hard work boning and cutting. Between 20-22 degrees was just right.
We were told at college that you never cut yourself with a sharp knife.the blade cuts and flows in the direction you are cutting but a blunt knife has to be forced and can result in changing direction with potential to cut you.growing up in the trade a man at a butcher shop near me was boning a beef chuck and the knife slipped and went straight into his thigh,he died right there were he was working.😢
Thank you 👍🏼
Australia
As a guy that's carried a pocket knife every single day for the last 25 years & owns probably 30 of them.. this is incredibly interesting.
Amateur knifemaker here, this video has answered so many questions, adding this to my favorites! +1 sub
This the cutting edge of science literally
I teach engineering students in a machine shop. You have just added content to my mill and lathe classes. You WILL be credited and I will steer students to this video for a deeper dive. Well done.
Yet another great video by one of the most underrated science channels on UA-cam. Thank you!
Watched at 5x speed, eh?
613k subscribers, and sponsored. Not sure about underrated lol. Either way it's good introduction to the basics of material properties in regards to cutting. Good stuff
As someone watching this video while also operating a CNC machine, I feel honored and thankful for everyone involved in getting us here. I wouldn’t have this job without them.
The Legend has blessed us with another Episode!
Great video, thanks. As a highly skilled mashinist, it warms my heart to watch this.
But a slight correction; it was not Watt the boring mashine was made for, but Thomas Newcomben. Originaly made to bore out canonbarrels. And it was only made possible by Darbys use of coke to melt iron, not charcoal. Otherwise enough iron could not be made, to cast a cylinder.
The same newcomben as the steam engine?
@@enja001 Yes, exactly. Darby made his melt in 1709, and Newcomben made his engine in 1712. The reason it was an atmospheric engine and not a steamengine was, the tecnologi was not good enough to make a boiler able to withstand the pressiore. The rivet was not invented yet.
From what little I know of this topic, almost every statement you made, is a documentary in its own right.
Another great production. Thank you NM 👍
Worth an entire college semester.
Which college did you attend ?
@@SuperYellowsubmarin Engineering Mechanic
This is super cool but more about metal and the history of metals than about cutting.....not that I am complaining:)
As a general machinist myself, i love seeing these deep dives into the history and processes of industry.
Working with CNC lathes and mills is so fun and satisfying watching it happen in front of your eyes.
Dude, what a well produced video! As a master's degree student at Materials Science you summarized several classes with maestry! Good job!
I poured Grey and Ductile Iron at Sather Manufacturing in Everett Washington State for good old Jody 😅 ahww awww and I loved it. I was doing Shakeout. We clamped molds for about an hour and we tapped out. We would pour from a Ladle weighing 1000# and carrying 3000# of bright orange almost yellow molten Iron and poured the molds we just clamped. After doing 9 Heats the first poured Castings were cool enough to shake out and not warp. We put them in the next room over with a power overhead crane. I started work at 11 am and didn't get to go home until All the molds we poured we're shook out and the sand shoved in the corner of the shop to be used to make tomorrow's molds. With a Bobcat Skid Steer 😏 I had so much fun and blasting a manhole cover hanging from the chain and knock off the sand with sludge hammer's was the highlight 🙂❣️🇺🇲🖖 9:04
Toolmaker & CNC programmer here for pharmaceutical and aerospace companies. This was an awesome watch thank you!
Great video, very informative but the title is very misleading, half the video was metallurgical history
Fascinating! At 21:30 there is an impeller being CNC machined. Do I recall correctly that this is a Space Shuttle part and is thought to be among the most complex parts ever to have been machined? Do you have references to this particular process?
You are making me psychotic man!
Every interest I pursue, either leads to one of your old videos, or you upload one while i'm pursuing it. And always being the highest quality. I'm glad I stuck around since the beginning of this channel!
11:32 "...could cut a 1m bore to an accuracy of 1.5..." my machinist brain thinks 1.5 thousands of an inch? 1.5 microns??? "...millimeters." Actually lol'd at that. Its crazy how quickly our machine tools advanced in accuracy and precision
Is this a reupload?
Yeah, it is. I remember watching this.
Open hearth furnaces were NOT more efficient than Bessemer converters but they did not introduce nitrogen into the steel like blowing air through it. Without nitrogen open hearth steel was much tougher especially at lower temperatures. We operated 1400 ton open hearths in the mid 1960s. Open hearths were replaced by basic oxygen furnaces - similar to Bessemer converters except blown with pure oxygen rather than air.
The pictures of dislocations was interesting, especially with them moving.
You need to do more research on the history of metallurgy. I'd recommend "making, shaping and treating of steel" as one source.
Later bronze swords were better than the early iron swords but iron was much cheaper so a noble could arm more soldiers. Adding Be to copper or bronze can increase the hardness to Rockwell C 45. Egyptians knew this.
I really enjoyed this. It was nice to see a video were all the clips were correctly selected and matched the narration.
You kind of skipped over cam drive, relay control, and pantograph in the lead up to CNC, though it's only tangential to the main topic.
I have a gigantic 3D printed CNC i desgined, so this was fun to watch 🙃 i can cut wood, plastics, aluminum, brass, amd copper. Its really cool to see how far we have come and how fast we are moving.
This video is reminds me of having to do an essay in school on a topic with no real information, so you kinda end up writing about something that is only slightly relevant to get enough words for the quota
Thank you so much for all your hard work making this video. Truly high quality content. 15 years ago the only place to learn anything like this was at university. Just amazing what I am able to learn in the comfort of my own house.
As a woodworker I found this really interesting. Great video
Excellent video, I learned a lot. Just wanted to point out that the reason why the discovery of the basic Bessemer process (using alkaline minerals for refractory lining) cut costs so much. As you said it allowed for the use of phosphorous-containing iron ores in steel-making. Phosphorous is a very common contaminant in iron deposits, and thus most deposits were unavailable for exploitation because the phosphorous contaminant would have rendered the steel brittle and useless. The cost of steel dropped when we no longer had to mine phosphorous-free ore (which often also has low iron content).
a must watch for all materials and mechincal engineering students
I was so enamored by the history of metal alloys that I forgot this video was about cutting until about the 10:40 mark. Great video. I'd love to see a game that incorporates such a granular progressions through metallurgy. Going from stone tools to copper to bronze to iron to pig iron to cast iron to steel to high speed steel.
Maybe not what you'd expect, but LOTRO has a system like that. From mining the ores, to smelting them with coals and such, to mixing the metals and making armours, tools, weapons etc.
@@MiD218 Really? I'll have to check it out
@@tectzas Yeah, besides me being a Middel Earth fan, that crafting system is a good chunk of why I like the game haha. You can check the LOTRO wiki to read all about how the crafting system works.
The topic of the video is something that you would never really think the history about, but it’s actually quite in-depth
a better title could have been "the science and history of cutting". great vid, pretty interesting
Thought this was gonna be the body/workout form of cutting
Would love to see a more in-depth history of the beginnings of metallurgy. Most certanly wasn't there one person who on day said "let's build a furnace, mix copper and zinc and create bronze". How did people come up with melting stones, so metal would come out of them? How did they discover the different properties of different metals and how did they manage to mix (alloy) them so they'd enhance each other properties thousands of years before chemistry became an actual science with methodical proceses?
3:02 The Bronze Age? Yeah I know him! He plays for the Lakers, right?
It's wild when you discover how interesting a boring mill actually is.
The footage of dislocations propagating was amazing, I'd never seen anything like it.
Not what I expected, but still enjoyed.
Was expecting to see how manufacturers develop cutters for different materials and situations such as interrupted cuts or hard metals.
As a tool sharpener, I can say that in most cases the exact definitions fall into the category of industrial secrets. Of course, some values can be determined superficially, but today we make unique tools for specific material quality and specific work. Cutting is thus much more efficient.
But he also mentioned coatings superficially, as well as outdated information. In ~5 years, the efficiency of the coatings was increased by >30%.
You forgot to mention crucible steel. The main tool steel used in the 18th and 19th centuries.
This it seemed to me to be more of a history than a science. That said, it was totally interesting.
5:40
I once put a 5cm stripped copper wire into a drill and the other end into a vice, after roughly 250 turns it broke clean at the drill. When I analyzed it, it was almost as hard as a steel nail, but would break when under too much load.
Cast Iron is Iron with a Carbon content between 2.06-6.8% Carbon (but only really usable until 5% Carbon)
There is an emo confused with the title of this video
Savage 😂
Damn that was so simply DARK
Lmao emo to CNC programer
Nah only a Biden fan
HA!! Well done. 🤣🤣🤣
Loved the video. I didn’t know what I was getting into and it has been illuminating. Thank you.
This is a good video I did not talk to the actual picture leading the video which is totally disappointing
From my understanding, limestone was used in blast furnaces since ancient times although the reason (i.e. the exact chemical processes) were unknown, people just knew limestone created removable slag that improved the final iron product. The other things you mentioned did greatly reduce the cost of steel production in the late 1800's, though, such as the Bessemer Process and the Oxygen Process, and others not mentioned (e.g. Siemens-Martin regenerative preheating). Still, excellent video, very high quality and production level!
Edit: Wait, you actually did mention Siemens' Open Hearth Processes. :)
The quality of the content on this channel is nuts!! Keep it up! 👏
This channel deserves millions of millions of subscribers. How dare you watch and not subscribe or like.
This channel is amazing. They take a totally mundane topic and make it fascinating. Thank you!
An episode describing how a knotter works on a hay baler would be super interesting.
You have no idea how much time I had been looking out this topic in my life !!
thx for all the info I didn't know
this isn’t what i thought it would be, but i still watched it
I love your automotive series and I would really love a video on automotive air conditioning !!!
I learned a few things! Great YT vid. One thing I have to say is that for the last 40 years people have said that the U.S. doesn't manufacture anything. We make the finest, and most expensive machine tools known to man. They ain't cheap. China sends more material and goods to us, by volume/mass. We send the most advanced and best equipment the other way. By cost/value? We export more than we import. Same with India/Egypt/Brazil... what have you.
7:50 seems a bit f confusion here puddling furnaces turn high carbon cast iron into low carbon wrought iron. Cast iron is produced by the blast furnace.
it is improper to say cutting shear force. any cutting has to start with high crushing stress otherwise the sharpness of the tool becomes unimportant. if only shear stress is important to cut, one can cut with blunt tool (other edge than sharp edge).
You made the mechanical engineer and metallurgists very happy 😁
Videos like this are awesome. Understanding micro-mechanics of common phenomena is great. Stuff like: cutting/shearing, tip deflection, friction
This is beautifully explained.
Thank you for saving the AD until the end 👍🏻👌 you just got my sub.
Congratulations. Wonderful content. You've just made a nice and gentle summary of machining, with details that I wasn't anticipated when I saw the video title… There are some statements that would lead to misinterpretations, like the bronze oxidation, but the overall content is remarkable.
missleading thumbnail, i thought I was going to learn the science behind cutting with/against the grain of steaks and cooking techniques
Super great video very informative and articulate I enjoyed it thoroughly thank you for sharing 🙏🏻
I have been watching your channel since the science of roundness and I always forget exactly how good your videos can be! lmao. When I clicked on this I did not expect an overview of this depth of the topics covered in both my materials and manufacturing classes in uni. Have you tried targeting the struggling mech E students yet?? A ton of students use youtube for help with course work/material and I do wonder how you would approach a video dedicated to material in a college level course. (like heat transfer or applied thermo).
Love these vids! This, flatness, roundness, of course the more ME focused vids have been my favorite so far.
By 7:56 you say low carbon, but cast iron is a high carbon alloy.
You have said this before so i thought it better to mention.
Man I thought this was something else entirely
REAL😭‼️
Some animals have various cutting capabilities, and animals even use tools. But what differentiates human from other animals is our ability to use stared energy.
Stored energy, such as fuels for burning like wood and oil helped keep us warm, cooking food (making it more edible), and do metal work.
This is cutting edge technology
This was about so much more than cutting!
exceptional primer on tooling history
Are there any materials with a lower melting points, capable of cutting material with higher melting points?
Just about any steel would cut platinum which is rather soft, but melts at a higher temperature than steel.
Dude @1:21 scared the crap out of me when he put his hands right under the working guillotine :O
The Metal Age not just gave human sharp formed object but sharpen the mind of human which evolve into extreme mind [idealism].
As far as I know, glass (man-made and obsidian) can make much more sharp edges than any metal. Metals are more resistant to alternating load and breaking, of course.
Fascinating video, as always.. thanks, I've learned a few things today!!
The machine that makes a machine tool different from any other is the use of the screw to precisely control the application of the cutting edge to the work. It's really that and not the application of power. A power tool isn't necessarily a machine tool.
A machine tool can be human powered and still be a machine tool. If you have to turn a wheel to make a cut happen, it's a machine tool. If you have to push to directly move an edge to make a cut happen, it isn't.
It's that the cut is constrained, guided by a way, and fed by a screw or lever (which themselves are basic machines) which makes a machine tool such.
A woodworking lathe where you apply a chisel you hold in your hand to a spinning workpiece isn't a machine tool, but it is a power tool. An electric drill you aim by hand also isn't a machine tool, neither is a router you aim and move about by hand.
A screw cutting lathe is, a mill is, even a pedestal drill is (although barely, because it has a quill you lower by turning a wheel). CNC machines of course all must be, but so too must the 'power feed' axies which a mill or lathe might have.
But it seems too often people equate 'machine' with 'has power from other than a human', and it just isn't so. A lever is a machine, so is a ramp or wedge, and the latter wrapped around a rod makes a screw thread, which is really just a fancy inclined plane which allows rotation to make controlled linear motion along the rod. That being used to change the position of a cutting tool, whilst another axis spins it, is what a screw-turning (metalworking) lathe is. It's not the spinning-ness of the work - it's the controlled positioning of the cutting edge.
What a great overview you made!
This is absolutely fantastic!
dude summed up my entire materials class in the first six minutes of this video, great job
Solid writing and editing. Well done.