Rusty Japanese Knife Steel Tested and WHOOPS!
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- Опубліковано 9 жов 2024
- Forging video here: • Forging A Knife Out Of...
Your questions left me with questions! I found the remains of 2 of the 5 original blades, did some testing and - SHEESH, I got this one wrong. See what you think!
The only marking I found on these knives besides the millimeter designation on their butts was a "万" kanji on the side of one of the handles. It apparently means "10,000" or "All" or "ichiman". It has a Chinese equivalent that translates to a few proper nouns. None of these terms yielded any helpful search results. I never found evidence of maker's marks on the blades. I'd still conclude these are production knives of some kind but a few were decent quality? If you know anything post in the comments section.
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Not only did you test other's theories, but published a video explaining what you got wrong. Props. Seriously.
Second, probably 1, but realistically, couldn't it be anything from korean war era sherman tank tracks to melted down flip phones?
Based on the etching of my knife I favor theory number 1. What do you guys think. Do you have theories of your own?
i have no idea about anything in that video. i just came across your channel and watch your videos because they are interesting and fun to watch. :)
I stand corrected good sir.. I believe after seeing you hardness test those, that I've just had bad experiences. Good detective work on the multi-steel discovery, I wonder if there were impurities (corrosion) in the mix as well. Either way I enjoyed it. And I'm happy to be proven the guy with the clown hat in this. 🤣 ya taught me something. Thank you sir.🤝
I tend to agree with you, some of them were one type of steel that hardened high and some were of a different steel that hardened less. You're correct that Japanese kitchen knives are typically hard and while the design is definitely of a kitchen knife, who knows how old some of them were and what they may have been initially used for? Do fillet knives or some specialty kitchen use knives perform better at 55?
Based on this I'd say not chinesium but different steels, maybe one or two were laminated ones, but chances are they were just different steels given the layer count is like 3-4 or something of the other kind of steel.
Difficult to say. I would rule out 3 but that’s about it.
Great follow up video. The “handle and all” foil pack normalization caught me off guard😂
I bet you could soak that blade at higher temps and get that carbon to migrate a little, not sure if it’s worth it but considering the crazy stuff you’ve done in the past with carburization and migration, it wouldn’t be out of place.
or even just case harden the edge? I bet he could have made a nifty "hamon" of sorts by case hardening in a wavey pattern, thus changing the appearance of that bit of metal after hardening.
Might also try a cryo treatment. If the knife is alloyed with vanadium/chromium the cryo would help with the migration
Theory 1 seems the most likely. Since this was a grab bag of knives at least one of them could have been an oddball with a lower carbon steel resulting in the lower hardness of the finished knife. Especially since you got what appeared to be consistent hardness results
I get a kick out of these breakdowns. Thanks for doing it. I cant even begin to guess how ya lost the hardness. Chop it up, canister it, add a small edge of 1095 and etch the hell out of it to showcase all the contrasts.
I think your first conclusion makes the most sense
I enjoyed the previous video and this follow up and all your videos. I enjoy how real your videos are you don't hide your struggles and learning and success!!
I’d have to agree with the first possible explanation. I’m not an expert on Japanese cutlery by any means, but in my experience etching san mai (with mild steel) or grinding the can off canisters, I find that mild steel etches noticeably different than even unhardened carbon steel. I would think that if you had mild steel or iron san mai it would have been exposed on the initial test etches. I think the possibility you have two different hardenable steels that don’t etch super distinctly prior to hardening is more likely. Also possibly worth considering is that the final blade appeared to have a decent amount 65 and 57 sections. With the extreme level of rust on those blades and as thin at they were, I’d almost think a large portion of any mild steel or iron jacket would have been corroded away and wouldn’t have left enough material left to make up that much of the metal in the final piece. But could also be completely wrong haha. That’s the fun part of experimental bladesmithing. Super interesting project regardless of the results!
Still a good result. A good lesson learned, two good videos and one happy guy that made 20 bucks from a pile of rust.
And here I had passed out and only vaguely remember my shock when you finally got a decent weld out of such corroded stock!
That was an interesting follow-up. Thanks, buddy.
Always love the genuine, unpretentiousness of your videos. It's so cool that you walk us through, not just the task, but the learning and thought process (or honest lack in some cases 😂). Thanks, and keep up the great content.
Thanks for the follow up. Great job.
Good luck on discovering the answer. As someone with only aspirations to get into blacksmithing and no experience, all I can say is an amount more or less or equal to one of these options may or may not be correct.
Couldn’t guess as to the steel sir. Thank you for the post
Some of those knives looked very well used, maybe they're different generations from the same maker. Who over tine just evolved their steel choices. That would account for the variations.
Whatever the case, I love the analysis and break down, super fun to watch
So you are a human! Lol 😆
I think you have a mixed bag. This was a really interesting video. It makes me think I need to do more testing with the random steels I use. Thank-you for sharing.
It's all right my friend even the most professionals can make a mistake but if you're always willing to admit your mistake that makes up for it as the old saying goes Life's a dance you learn as you go
I don't see any problems here. First, you made a great video about constructing a knife from old knives. The knife came out pretty cool, despite the paucity of useable material you had to start with. I think all of your testing points to your conclusion that you were starting with some high quality steels and some low quality steels, but not enough of either one to do rigorous testing beforehand. You even got another great video out of the process in exchange for a lesser knife. Next time you just need a lot more rusty knives to start with so you can weed out the nonhackers, which will be yet another cool video. Win win win!
rt
always enjoy the videos! keep up the good work steve
This is good science.
I'd tend towards 1 as the most simple, parsimonious explanation. If 2 were true than you'd expect a more complex etching pattern. If 3 was the case than you'd expect the knife to be much softer, with thin bands of darker material on the etch.
Man I am finding these to be so intriguing. With my limited knowledge as a user, guessing between #'s 1 & 2. Fairly certain that at least one of the blades was a laminate (San Mai) due to what the etching of the knife showed. The grinding is an interesting point too. What if one of the knifes actually were either and/or both, Hitachi's White Paper and their Aogami Blue #2. A Huge fan of the SB steel-it's one of my favourites
Steve
Good follow up video brother.
I'm thinking that all were laminated steel blades and all the corrosion and rust pits skewed the results and also not doing a proper test at beginning.
awe you burnt that lovely handle off ...and you did make damascus without even knowing lol
fascinating process all told though thanks for that.
I think your knife was going to be a better utility knife than the original ones simply because of toughness and thats usually what matters for me .
10/10 for this and the previous video
Carbon loss during the welding and forging of the knife? I love videos like this!
There was prob a small amount
This was really interesting and a very cool piece ! I think its either option 1 or 2 as well. Maybe one knive was an oddball lamented knife but you are right it was probably just a monosteel knive that was a different hardenable type.
Id love to see you do a knife made from already made "Damascus" knifes that are on amazon or eBay. Im interested to see if they are even actual layered steels and if they can be forged together.
ya was wondering if you might take into consideration they have two steels used for the back and the edge. :)
I’m gonna go with 1, who knows what they truly are made of could be washing machine and old brakes
heheh
Not sure why you said "most Japanese kitchen knives aren't hardened to 65"
As a professional chef of 15+ years all the aogami 2 and super blue knives I've used or handled were 63-65 hrc
And why you ask? Easy... edge retention.
Harder steel gives better edge retention. And aogami (and shirogami) steels are made for high HRC, low edge angles, for maximum performance.
Theory #1 is the most likely in my opinion as well. Maybe the key (in hindsight) would have been to etch the knives after cleanup while still hard
Love the fact you went back to re-science the knife. Cool learning experience for all.
In rewatching your original video a second time, I cant say I would have made any different assumptions. You checked and checked. All cards came up monosteel based on spark and hardness throughout. Really enjoyed this.
Gotta ask. What made you go back and recheck?
Comment section
As a Japanese kitchen knife collector my bet is on two being the most likely. The reason is that it is pretty common for a Japanese knife made in either the sanmai, warikomi or awase (basically one side is hard steel and one is soft typically done on single bevel knives) style to be made of something like aogami with a softer steel to protect the more brittle hard steel core/cutting edge. Typically Japanese kitchen knives range from 58 to 65hrc or possibly 68hrc so with mono steel I would not expect 55hrc but I would expect it from cladding. Granted the knife that you made could very well be 58hrc as far as I know. I am just basing this opinion off my knowledge and you saying that it is 55hrc.
I would go with #1. You grabbed 2 or 3 different types of mono and tried forging together. Which takes me back to my original comment of using electrolysis to remove the rust. Then by cutting the knives, you could spark test each knife by using only a small portion. Then, I'd throw matching mono steels into a canister and go from there. Grinding the rust off those thin blades cost quite a bit of good steel since blades were badly pitted. Am no expert, just know what has worked out best for me.
Another vote for theory 1. Maybe it would be good if you welded high carbon steel for blade area.
As an expert (ex=has been... Spurt=drip under pressure) on this type of issue. The material you used is definitely metal 🤣
🙏
i think they were made out of metal.
love the videos
Furnace conditions were all identical? Because heat treatment can, depending on furnace atmosphere, carburise or decarburise the steel. If some of that was done in a stainless steel sheet pouch, where others were done exposed to air, or direct flame, you might get differences in effective surface carbon content.
From the sparking, I am going to guess they're all made from Hitachi Blue. Given that all the knives were of the same style and finish, almost as if 'production-lined', I find it hard to imagine that a smith would make some knives from one metal, then switch to another metal for others of the same design and finish, the variation in spark colors across the five, coming from differences in thickness and level of corrosion, rather than the metal used by the smith 👍👍👍👍
I think Japanese kitchen knives are usually harder than western knives.
Do you think pre heat treated steel sparks the same as post heat treated? Was your O1 hardened?
No it was annealed from factory. Hardened probably generates more sparks because it takes more work / gear to remove? Good question I’ve never tested that.
Option 1 is likely the correct one... had a couple with crappy steel & happened to pick one or more of those to get enough material for your knife. =(
That’s one way to get the handle off. 😆
😎
I feel like another ding to the laminated construction theory is that you'd have likely had a harder time forge welding those billets if something like an iron jacket would have been present. I'm a theory #1 vote.
I dunno, I think 1 fits the bill. Your guess is much better than mine
Could it have had a bunch of decarb on the knifes that you didn’t completely get ground threw while cleaning the rust off? Then when you layered it that caused multiple striations in hardness and a layered pattern when later etched.
I will say generally when I see monosteel knives made of shirogami, or aogami they cost a pretty penny. I would have loved to see what these knives looked. Like before they were corroded. Some of them looked pretty bad.
I'm actually torn between options 1 and 3, there are so many possibilities. I mean from what I can tell they were so rusted you can't even see the kanji they marked the blade with. Do that's pretty corroded.
Thank you
I lean towards the first option. Hitachi's white and blue paper steels both have carbon contents in excess of 1% (Some are as high as 1.3%) so it ain't those. Moreover, those blades looked positively ancient, like, archeological "as found" condition. The way the grips cracked around some of the tangs and the way the tangs were reduced to a flaky black oxide pastry lead me to believe that the raw poplar was soaking up moisture from the air and holding it against the tangs like a sponge for a LONG time. 100 years old? Likely! So I'm leaning towards pre-war. If this steel was made in a tatara furnace (which was a lot more common in the Taisho era than it was in the Showa era) then it came out in blooms of roughly 3 grades. The highest carbon, hardest stuff would've been reserved for things like woodworking tools. The lowest grade stuff would've been comparable to mild steel. Now the mid-grade stuff would've started out with around 0.6% carbon and trace amounts of impurities like silicon and whatever else was in the black sand the steel was smelted from. After being heat treated in an oxygen rich environment, well... I think those knives with burst handles were that and the others were something else, maybe not as old.
Really interesting indeed, dude. Really curious results!
But, honestly, I know almost nothing about this stuff, so I go with your guess. 😬
Anyway, stay safe there with your family! 🖖😊
Rebar is generally some flavor of carbon steel, isn't it? Not like super high carbon, or very consistent (doesn't need to be), but carbon nonetheless.
These look more like the knives used at the dock not necessarily chef knives. Probably higher production run. Any chance the powdered steel added would negatively affect the hardness?
Would help
That hurt watching you put that beautiful knife in the oven lol
I suspect you have fairly cheap production knives, certainly nothing one would expect to have the effort put into it that san mai requires. I lean to #1 as the most likely (Occam's Razor, and all that) and applaud you for your followup.
If it was a bunch of multisteel knives, could there have been significant carbon migration from the high carbon, 65HRc steels, to the low carbon jackets and made a medium carbon steel? Some smiths add a layer of nickel between the edge steel and wrought iron or mild steel cladding to avoid exactly that. Whatever the explanation, very cool video investigating where you could have gone wrong.
Anything’s possible. I feel lost on this project.
Ever see anyone add carbon to steel by putting it in sugar and then the forge? It does add Carbon.
If I can get some spare cash I would love to put a bundle of pocket knife blades together that I can't use and happily send them to you and see if you can make something out of them but are you in the US so I can send them
Bro you do a great job. I think you don't need to respond internet trools. Even thou I like it.
So that’s what happened to all that “metal” that rancher found in Roswell back in July, 1947!
Back to mothership?
I think those are all monosteel. I'm leaning towards 1.
Cool video
I think one of problem is that some people have weird idea that Japanese knife = amazing steel.
Well no, most of them use random aloy steel, lots of use crappy steel. Even when you get knifes from one batch you can get few differences in quality.
Those knifes look like cheap ones that restaurant or markets use for chopping vegetables and meat, you get them in bulk and don't care about fancy handle or layered steel. Those are knifes that you use for whole day work, not fancy sushi cuts on fish one or two times per day. You sharpen them every hour using other knife so you don't care about quality of edge.
So my bet is that steel is just random quality aloy with enough carbon to not bend like plastic and with some aloy(chrome etc) to keep rust away a bit better.
I tend to agree. I don’t think they had kanji on the blades and the symbol on one of the handles was generic and looked printed in a modern style.
Steve, so how about you now take all of the remaining steel from those knives you have left, and the one you made, add more steel and make a new knife? Just a silly thought. Humor intended.
How much carbon could have leeched out during the forge welding? If you have thin steel layers of low and high carbon steel in a laminated construction you'd probably get a lot of carbon migration during forge welding. Perhaps the carbon just diffused and evened out between the different carbon steels?
Some but only surface deep I think.
unless they were expensive knives to begin with, i would have a hard time believing they were bue mono steel, every less expensive japanese knife ive seen that uses one of the aogomi steels is laminated. msbey there is another less espensive alloy steel they are using.
i think the ones that your haviing heat treating issues with are probably sk5, this is a very common lower end steel in japan and it really cant be heat treated over 60 or so.
I suspect they were all monosteel, it seems to be the most likely scenario.
Ah Ha! Every mid to decent Japanese knife I own is a San-mai sandwich.
I just dont see them doing multisteel construction on production knives, unless they managed to rob a takefu warehouse or something for a fancy plate of san mai.
Probably a combo of different steels, if there's some alloy predominant in there it might take to a medium quench speed oil or a plate quench but just off the top of my not exactly brilliant brain when it comes to Japanese steels- just not a lot of the higher alloy tool steels are in the 65hrc bracket. Most of them you can get into the low 60's with, but almost universally its the high or very high carbon stuff to get into the 65+ range.
Plus, just a sort of arbitrary observation, they do rust like carbon steels, most of the higher alloy stuff tends to be a bit resistant towards that deep pitting effect where its peeling off in slabs
So, I guess its a mix of 1-2 steels. Don't really have much more to add
Theory 2. Its pretty obvious. 1: I really doubt a kitchen knife made in Japan would be medium carbon monosteel, the culture just wouldn't allow it. The only way i can see that happening is if it was made from cheaper tamahagane. 2: If at least one of them had a San Mai jacket, which is more likely, all the welding and forging it has been through would have caused enough carbon diffusion for it to harden like medium carbon. 3: If they were all San Mai, that's a pretty heavy ratio of low to high carbon. The dark lines in the etch would have been a lot thinner.
I think there are many monosteel knives from Japan, though. Especially production. The only chance I had of figuring this out for sure is long gone.
@@GreenBeetle I'm making a pretty broad assumption on that first guess, I'm a long way from being qualified enough to say with any certainty.
I will pick number 3, japanese knives usually are made of two steels, high carbon and mild steel, the portion of high carbon steel is minimal and is 'glued' to the mild steel with iron powder
You are awesome 🤘🤘
Its hard to imagine someone in Japan making a carbon steel kitchen knife from one piece of steel. Just about all traditional cutting tools (knives chisels plane blades ) are laminated.
From Japan? There are many monosteel knives made in Japan.
@@GreenBeetle the markings on the wood handles look like they are traditional style knives, unlike the modern Santoku or Gyuuto style, but hey I could be wrong, I'm talking as a Japanese person, not a Knife person. :)
I think they were chineseium sold by a japanese maker
Holy Crap. You just put the knife with the finished handle in the oven!! ??? I first thought you where BS itting us. But No....
This action won't get you any bonus points to get into knive makers heaven. Still bothers me....
it broke my heart, that you basically destroyed the knife.
but hey, we got a bit smarter ^^
The edge was too toothy to be a good kitchen knife. It was usable but I’d never have sold it and it’s bother me every tim I handled it 😀
They were probably made of unicornium magicum, and you cut them up.
I knew it. They were probably from an ancient katana and doing the right pose w a woosh noise caused them to fly back together into a sword.
I would guess that most or all of them were made of what is usually inscribed as "Japanese carbon steel" which is kind of a generic good quality tool steel used for many applications including lots of workhorse type cutlery. I have a number of old knives in my collection which l have restored which use this steel, and they are all very good except one, which just refuses to take a good edge. it takes a useable edge but not a truly good edge. Point being that it is possible that some of the steel you used might just have been defective. But it is puzzling why your blade comes out so much softer than the other pieces.
You worked you a$$ off makeing that last video. I dont think anyone should be giving you any grief at all about it.
3
I'm gonna guess "steel"
lawn mower blade ish maybe?
Do you know anyone with an X-ray fluoroscopy gun?
Jeebus
Lesson learned don't use un known steel, LOL
🇮🇩👍👍👍😍
Well.... that's answer what mybmind kewp telling me.
Now test the wood if it a laywr steal or not.
1
Cheap Japanese knives
Hey Steve, great follow up!! I agree with you. At least 2 of the knives were solid good steel. With the others being meh steel. I have some hitachi blue on hand and I'll DM you a vid of the sparks on Instagram.
Nice, ty
@@GreenBeetle your very welcome!
i watched the other video too, cheap jap knives are just sk steel no lamination and im gueesing most home users would have them instead of paying hundreds of dollars, white and blue steels are very brittle and need a bit of work to maintain so i would guess they're sk steel