"Edge Packing" is not really an old wives tale, but as you say it is a method to increase the dislocation density which in turn leads to the nucleation of new grains, You can find edge packing described in numerous blacksmithing and tool making references from the early 1900s. However, it actually goes back to an 1868 paper written by Dimitri Tchernoff, who ran an industrial forge shop in Russia. He observed the need to control the forging temperature to control grain size in his large forgings. He was making cannon. You have to remember that at this time and well beyond, the steels in use did not have the grain pinning elements aluminum, vanadium, niobium or titanium. The ONLY way smiths of that era could control the grain size was by getting the smallest possible grains through the forging process (what came to be known as edge packing) followed by heat treatment temperatures that were on the low end of the effective range to form austenite. Today, most steels contain some kind of grain pinning element, such as aluminum, and we can utilize austenitizing temps up to about 1750 with the simple steels and still keep the grains small. We do not need to use edge packing. If we do choose to use it, you still have to keep the austnitizing temp at or below 1750 F for most steels, otherwise the benefit of what should really be called "cold forging" is lost. (Note that I am a hobbiest knife maker/blacksmith but a professional metallurgist specialising in large steel forgings so for me, effective control of grain size is an absolute requirement to meet customer's expectations.) In industrial practice there are some grades and product forms where grain size is controlled by cold forging or rolling of plate, but most of the time it is done strictly via heat treatment cycles. Since you were working with 52100, you likely would not see much benefit from edge packing at all, but if you tried this again with 1080 you likely would. If you really want to experiment with this technique, you can simply forge a flat bar to a thinner dimension cold, then heat treat it like you would a knife. After heat treat, break the bar and look at the fracture surface. Compare the surfaces of samples subjected to cold forging and normal forging cycles. You don't have to go to the trouble of make a full knife to experiment with the process.
Just like the carbon atoms in the metal lattice induce "tension", dislications in the lattice induce "tension". Creating these dislocations is part of the process "work hardening" - and just like carbon, an increase in the amount of dislocations makes the metal stronger, to a certain degree. You can have too much carbon/too many dislocations, making the metal weaker. Super interesting to see you experiment. It makes you wiser.
I really admire your sense of discovery, as well as your dedication to perfection and pushing the limits of your craft. Beautiful work, but it's really amazing the thought that goes into your work. Thanks for sharing!
This process seems very similar to the "Peening" welders do on some materials. Also I have seen "Metalax" stress relief machines that vibrate metal products at certain frequencies for certain amounts of time to refine grain structure... usually used for connecting rods and crankshafts in race engines. Always enjoy your videos.
Interesting, I've seen videos of Japanese kitchen knife smiths do a lot of that cold forging on blades both by hand hammering and using a power hammer. Thanks for sharing.
Knife Talk by Ed Fowler. Great book. I am studying this like the Bible. He loves 51200. He has the same attitude of experimenting and sharing knowledge. To me this is great content!
It's an interesting experiment. I've seen a lot of japanese smiths cold forging kitchen knives before heat treatment. I'm going to have this a bash too.
Congratulations on your newest trophy Elijah. As always this video was Informative. Also I completely agree with you about the not learning what is the point! Thanks again!
As you pointed out, there were a lot of variables in your experiment. I'm no scientist, but the lab classes I took emphasized only experimenting with one variable. It would be interesting to see your cold forging results if that was the only thing different from your usual 52100 process, meaning using your HT oven and testing only the cold forging.
Wow edge packing. I haven't heard that term in YEARS! Last time I saw any real discussion about it was around 2007 or so on a forum. Of course that was around the time I stopped frequenting forums as much.
Old style scythes used this principal. Cold working the edge increased its hardness enough to Stay sharp longer in the field. I imagine it is fundamentally the same as hot working but of course hot working guarantees homogenous grain size wereas cold forging depends on the Smith. Although I think when you heated it up after the cold forging you likely undid all of your work. I don't really know
Just read something on this. Hammering steel into itself is called upsetting. That's what the equivalent of edge packing. Compacts steel grains, therefore, more atoms and more grains.
Appreciate your videos and the want of learning. "Knifesteel Nerds" have provided a mass of testing and information on steel structure & phases with lab controlled, repeatable tests using sophisticated equipment and peer reviewed material.
I find it strange that anyone in this arena would doubt cold forging 'does anything' or it's held at arm's length as an old wives tale, as they probably own products that were cold forged unbeknownst to them. It's been a standard industrial practice for a very long time, not the least of which is regularly found in higher quality gun barrels. Without going into white paper technicality, cold forging is typically done with hydraulic or pneumatic hammers to refine grain structure at room temperature. Steel inherently has dislocations regardless of how it was forged as that is a core material property of steel in general. When seen through a microscope, the carbon elements are the 'dislocations' filling in voids between iron irregularities; the idea behind cold forging is to condense the base structure without additional heat that tends to induce fatigue and weakens the bonds between the elements on a molecular level. Outside of methodical lab testing, it's often seen from the laymen as something of a trivial matter as one can still hot forge steel to incredible strengths within a defined and expected performance envelope. Everything has a material failure point, but when you absolutely need to rely on something for an extra 5 or 10% performance (just theoretical values here for the sake of explanation), a more broadly cost-prohibitive process becomes more viable in specialty cases. TLDR version: cold forging adds a percentage of extra resilience when put through extreme use and abuse.
During your studies, have you found any indicators/rules of thumb/ways to know when you have cold forged a particular steel "the right/optimal" amount to achieve the best grain refinement?.. or do you need to work that out by yourself through countless tries i.e. by trial and error? I hope for you, it is relatively easy to figure out - and that it only takes a short amount of time to cold forge each knife to obtain proper refinement, since that would really save time, skipping some of the longer heat treatment processes. Keep learning, and keep teaching. It is SUPER interesting! (I have a Masters Degree in geology, back from 2001, and took a class on Material Science, so I know a bit about crystallinity, crystallography, fase diagrams, fase transitions and the likes. I actually understand the words you use, and it pleases my inner nerd to watch your videos, since I have not used my degree for many years). 👍👍👍
I've read that common practice is to hammer the steel at least once on each side of the blade. In that case it was done with a power hammer, so perhaps more would be required with a hand hammer.
I watched one of Muray Carter's videos and he cold forges a lot but he works in Chinese or Japanese stainless steel . He didn't talk about it but he just did it.idont think he wanted to give the process a bunch of attention ?
I would think any "edge packing", grain refinement or what have you would be undone during the heat treatment and you'll be left with the steel properties from the heat treatment and not any prior work
Hey, new subscriber here. I litterally just subscribed. Ive noticed that you have some banner somewhere in the shop that sais bladesmith and blacksmith. Would you like to attempt an integral s guard? I think as a blacksmith, that shouldnt be a massive problem and we have way to less integral guards on youtube.
@@FireCreekForge Perlite is also a different product than Vermiculite, and functions differently than perlite when it comes to heat and water. Perlite is made from volcanic glass, whereas Vermiculite is made from silicate material - which is generally what the majority of volcanic rock is made of - but they have entirely different physical characteristics. Vermiculite has a structure that sort of folds in on itself, and Perlite is more like Styrofoam popcorn. While they are similar to each other, they are not the same thing structurally, and often not in practice, either. For your uses their performance is probably close to equal, but they definitely aren't synonymous.
I’m 62 and I always learn I appreciate the way you Explain what you’re doing and why.
God bless and I’ll see you in the next video.
I am a newbie Knife maker. I love the "doctrine" Preach it brother! You explain it well.
"Edge Packing" is not really an old wives tale, but as you say it is a method to increase the dislocation density which in turn leads to the nucleation of new grains, You can find edge packing described in numerous blacksmithing and tool making references from the early 1900s. However, it actually goes back to an 1868 paper written by Dimitri Tchernoff, who ran an industrial forge shop in Russia. He observed the need to control the forging temperature to control grain size in his large forgings. He was making cannon. You have to remember that at this time and well beyond, the steels in use did not have the grain pinning elements aluminum, vanadium, niobium or titanium. The ONLY way smiths of that era could control the grain size was by getting the smallest possible grains through the forging process (what came to be known as edge packing) followed by heat treatment temperatures that were on the low end of the effective range to form austenite. Today, most steels contain some kind of grain pinning element, such as aluminum, and we can utilize austenitizing temps up to about 1750 with the simple steels and still keep the grains small. We do not need to use edge packing. If we do choose to use it, you still have to keep the austnitizing temp at or below 1750 F for most steels, otherwise the benefit of what should really be called "cold forging" is lost. (Note that I am a hobbiest knife maker/blacksmith but a professional metallurgist specialising in large steel forgings so for me, effective control of grain size is an absolute requirement to meet customer's expectations.) In industrial practice there are some grades and product forms where grain size is controlled by cold forging or rolling of plate, but most of the time it is done strictly via heat treatment cycles. Since you were working with 52100, you likely would not see much benefit from edge packing at all, but if you tried this again with 1080 you likely would. If you really want to experiment with this technique, you can simply forge a flat bar to a thinner dimension cold, then heat treat it like you would a knife. After heat treat, break the bar and look at the fracture surface. Compare the surfaces of samples subjected to cold forging and normal forging cycles. You don't have to go to the trouble of make a full knife to experiment with the process.
Thanks, great comment!!
I have learned a lot of the technical side of things from watching your videos so thank you for sharing your knowledge and experience with us
Just like the carbon atoms in the metal lattice induce "tension", dislications in the lattice induce "tension". Creating these dislocations is part of the process "work hardening" - and just like carbon, an increase in the amount of dislocations makes the metal stronger, to a certain degree. You can have too much carbon/too many dislocations, making the metal weaker.
Super interesting to see you experiment. It makes you wiser.
Thanks! Yes this is true however work hardening isn't the goal in this case, but the re-nucleation sites created during coke forging.
I really admire your sense of discovery, as well as your dedication to perfection and pushing the limits of your craft. Beautiful work, but it's really amazing the thought that goes into your work. Thanks for sharing!
This process seems very similar to the "Peening" welders do on some materials. Also I have seen "Metalax" stress relief machines that vibrate metal products at certain frequencies for certain amounts of time to refine grain structure... usually used for connecting rods and crankshafts in race engines. Always enjoy your videos.
Interesting, I've seen videos of Japanese kitchen knife smiths do a lot of that cold forging on blades both by hand hammering and using a power hammer. Thanks for sharing.
Knife Talk by Ed Fowler. Great book. I am studying this like the Bible. He loves 51200. He has the same attitude of experimenting and sharing knowledge. To me this is great content!
It's an interesting experiment. I've seen a lot of japanese smiths cold forging kitchen knives before heat treatment. I'm going to have this a bash too.
Congratulations on your newest trophy Elijah. As always this video was Informative. Also I completely agree with you about the not learning what is the point! Thanks again!
No Rockwell tests? Come on brother, bust that thing out!
As you pointed out, there were a lot of variables in your experiment. I'm no scientist, but the lab classes I took emphasized only experimenting with one variable. It would be interesting to see your cold forging results if that was the only thing different from your usual 52100 process, meaning using your HT oven and testing only the cold forging.
Yes, that is a good point
Wow edge packing. I haven't heard that term in YEARS! Last time I saw any real discussion about it was around 2007 or so on a forum. Of course that was around the time I stopped frequenting forums as much.
Thank you
Thank you sir
Old style scythes used this principal. Cold working the edge increased its hardness enough to Stay sharp longer in the field. I imagine it is fundamentally the same as hot working but of course hot working guarantees homogenous grain size wereas cold forging depends on the Smith. Although I think when you heated it up after the cold forging you likely undid all of your work. I don't really know
Great job!
Just read something on this. Hammering steel into itself is called upsetting. That's what the equivalent of edge packing. Compacts steel grains, therefore, more atoms and more grains.
🏆, there it is.
Appreciate your videos and the want of learning. "Knifesteel Nerds" have provided a mass of testing and information on steel structure & phases with lab controlled, repeatable tests using sophisticated equipment and peer reviewed material.
Thank you! Yes I have found his info to be helpful
🏆HaHa, I really enjoyed that, you're the best!
I find it strange that anyone in this arena would doubt cold forging 'does anything' or it's held at arm's length as an old wives tale, as they probably own products that were cold forged unbeknownst to them. It's been a standard industrial practice for a very long time, not the least of which is regularly found in higher quality gun barrels.
Without going into white paper technicality, cold forging is typically done with hydraulic or pneumatic hammers to refine grain structure at room temperature. Steel inherently has dislocations regardless of how it was forged as that is a core material property of steel in general. When seen through a microscope, the carbon elements are the 'dislocations' filling in voids between iron irregularities; the idea behind cold forging is to condense the base structure without additional heat that tends to induce fatigue and weakens the bonds between the elements on a molecular level. Outside of methodical lab testing, it's often seen from the laymen as something of a trivial matter as one can still hot forge steel to incredible strengths within a defined and expected performance envelope. Everything has a material failure point, but when you absolutely need to rely on something for an extra 5 or 10% performance (just theoretical values here for the sake of explanation), a more broadly cost-prohibitive process becomes more viable in specialty cases.
TLDR version: cold forging adds a percentage of extra resilience when put through extreme use and abuse.
Also: shot peening
During your studies, have you found any indicators/rules of thumb/ways to know when you have cold forged a particular steel "the right/optimal" amount to achieve the best grain refinement?.. or do you need to work that out by yourself through countless tries i.e. by trial and error?
I hope for you, it is relatively easy to figure out - and that it only takes a short amount of time to cold forge each knife to obtain proper refinement, since that would really save time, skipping some of the longer heat treatment processes.
Keep learning, and keep teaching. It is SUPER interesting! (I have a Masters Degree in geology, back from 2001, and took a class on Material Science, so I know a bit about crystallinity, crystallography, fase diagrams, fase transitions and the likes. I actually understand the words you use, and it pleases my inner nerd to watch your videos, since I have not used my degree for many years). 👍👍👍
I've read that common practice is to hammer the steel at least once on each side of the blade. In that case it was done with a power hammer, so perhaps more would be required with a hand hammer.
I watched one of Muray Carter's videos and he cold forges a lot but he works in Chinese or Japanese stainless steel . He didn't talk about it but he just did it.idont think he wanted to give the process a bunch of attention ?
He explains the process in detail in his book
What do you think about fiction forging? I've watched a video demonstration, but I don't know if it's just a gimmick
I would think any "edge packing", grain refinement or what have you would be undone during the heat treatment and you'll be left with the steel properties from the heat treatment and not any prior work
The purpose with cold forging here is to create re-nucleation sights for new grains, which is completed upon heating to austenitizing temp..
What happened,,,? I went cross-eyed the first 3 minutes...lol
Hey, new subscriber here. I litterally just subscribed. Ive noticed that you have some banner somewhere in the shop that sais bladesmith and blacksmith. Would you like to attempt an integral s guard? I think as a blacksmith, that shouldnt be a massive problem and we have way to less integral guards on youtube.
May have to do that sometime. Thanks for subscribing!
I believe that's perlite, not vermiculite.
Well yes perlite is the name of the brand
@@FireCreekForge Perlite is also a different product than Vermiculite, and functions differently than perlite when it comes to heat and water. Perlite is made from volcanic glass, whereas Vermiculite is made from silicate material - which is generally what the majority of volcanic rock is made of - but they have entirely different physical characteristics.
Vermiculite has a structure that sort of folds in on itself, and Perlite is more like Styrofoam popcorn. While they are similar to each other, they are not the same thing structurally, and often not in practice, either.
For your uses their performance is probably close to equal, but they definitely aren't synonymous.
First !!!!!
I think you need to trim your beard! Your videos are super!
I don’t want to burst any bubbles here but uh…edge packing is used on bronze weapons. Sorry.
We are in Russia, we are getting old to use rolled metal of your manufacture, why are you engaged in metal forging, it is unclear?