The Truth about Cryo Tempering

Danbo said:
Are you trying to say that 440C is the same thing as A6?
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Depends on the origin. It's usually the same, sometimes vanadium is added, also sometimes more chromium. No way to positively identify without a spectrum analysis. Batches vary more than the labels, in this economy. Impurities are more common now, etc......If you want an independent analysis of your stock, send me an e-mail.....I'll see if my lab guy can accomodate you.

Now for the testing.....Yeah, it wasn't me that proposed this, but it would make an interesting experiment, don't you think? IF, we can leave out the egos, the pre-conceived testesterone, and really want to find out, right?

I'll accept, conditionally.....The blades need to be of useable specs. In other words, something YOU would be happy to sell as a working blade. It should pass a bend test, minimally. Maybe 90* without breaking. Average size, and the tester sharpens both on standard equipment. Blade mag puts out some standards, any of those would do. Nothing wierd, no Vasco, or Stellite. The tester(s) should post their history, their stock preferences, and why they can be impartial. I'm easy to please.

Now, I cannot make a blade for this test. Why? Because I'm still experimenting with my own methods. I'll gladly accept a blade from someone who has used a standard tool steel exclusively for years, though. It takes years to become intimately familiar with a particular stock, IMHO. If anyone here desires to prove his blade against a STANDARD SS, the let him speak now or forever hold his peace :eek:

Now, I understand that those that hold a particular alloy dear, has an emotional attachment to his work. IF you would like to find out if your choices hold water, then we'll do it. I'll gladly accept any and all conclusions drawn by independent testers. Is this what you have in mind?

Mike (not trying to cause a ruckus:)

One more thing.........I've told you what would work for me, tell us what type of steel you plan to use?? And what HT.
 
I'll add this to the discussion. I've always had my D2 blades cryo treated so I don't know if they are better with or without. I made some stock removal 5160 knives that were only heat treated. The D2 knives stay sharper longer and are less prone to edge rolling and chipping. The 5160 blade did not stay sharp as long and was more prone to edge rolling and chipping. A forged 5160 is probably better.
Scott
 
Warrant said:
I haven't made near the the number or quality of blades that most of you here have, but I'll bet I've done more research on metals......40 years of it. Not having any initials by my name doesn't give me expert status, but here's my opinion, anyway.....



Cryo is the only way to get most SS into the realm of suitable cutlery steel. And then, it's marginal..........440C (A6) is barely abrasion resistant BEFORE tempering.............afterwards, it's very marginal for blades...


Which is why (and this will get me in hot water, I suppose), I have never seen, nor heard of, any current marketable SS that will cut/hold an edge, as well as plain old O1, D2, A2, 1095, 5160, 52100 series stuff).. Properly HT, of course........no cryo needed.



Mike
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I have to say you're wrong. Properly heat treated 440C will hold a edge as well, and as long, if not better, and longer than 01.
I have both in my shop(I made them), and they see very hard use. I prefer the 440C blade.
They were both professionally heat treated.

This old nonsense of saying 440C is garbage had, I thought, died out with all the other 1920's prejudicial tales of the evil stainless steels.:rolleyes: ;)

Just about every story of 440C not holding an edge, can usually be traced back to the maker, and improper heat treat.:eek:
 
440C is a good knife steel, along with most any other of the "standard" steels we use today, stainless or carbon, high carbon alloy, etc.

You must remember that some steels are better suited for this purpose or that and these properties were developed for those specific uses.

The same goes with different blade designs and geometry.

The old stainless vs. carbon steel argument has been around a long time before this thread was posted.

You'll see just as much, if not more passion in this argument than you will in any political argument.

This is fruitless...

Work with what you are comfortable with, do the best you can and that is the best knife you can produce, period.

Craig
 
C L Wilkins said:
440C is a good knife steel, along with most any other of the "standard" steels we use today, stainless or carbon, high carbon alloy, etc.

You must remember that some steels are better suited for this purpose or that and these properties were developed for those specific uses.

The same goes with different blade designs and geometry.

The old stainless vs. carbon steel argument has been around a long time before this thread was posted.

You'll see just as much, if not more passion in this argument than you will in any political argument.

This is fruitless...

Work with what you are comfortable with, do the best you can and that is the best knife you can produce, period.

Craig
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........Amen!!:D
 
Warrant said:
Depends on the origin. It's usually the same, sometimes vanadium is added, also sometimes more chromium.
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Without getting into all the other stuff you have mentioned(stainless vs carbon steels), I have to say that you're clearly wrong about the A6 and 440C comparison. So wrong, in fact, that you must be delirious or seriously misinformed. 440C is a bearing quality stainless steel containing 16-18 % Chrome. That's about as stainless as knife steels get. A6 is more like a die tool steel and only has like 1 % Chrome. No corrosion resistance whatsoever. It's like comparing apples and a hot pepper. Two completely different types of steels. ???
 
I was wondering who was going to say what, when. You showed pretty admirable restraint, Danbo!

Now someone has to point out the ludicrosity of expecting a normal stainless blade to bend 90 degrees as a qualifying test...........
 
mete said:
Yes Danbo.At least somebody realized that.
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Oh, Im sure a few others realized it right off, but in my case, I figured that pointing out one inaccuracy at a time was enough for now.;) :D
 
fitzo said:
I was wondering who was going to say what, when. You showed pretty admirable restraint, Danbo!

Now someone has to point out the ludicrosity of expecting a normal stainless blade to bend 90 degrees as a qualifying test...........
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Et tu, Mike?:D ;)
 
Personally, I'm very excited about this test. My favorite steel is 5160, but the steel I use on all of my knives is 154cm. I don't think stainless or carbon steels are crap, I'm just really interested to see how the perform side by side. While we're at it, is anyone willing to test a cryo vs non cryo steel?

- Chris
 
Hesparus, let's compare apples with apples .For example the hypoeutectoid [below .80%C] steels will have considerably lower wear than the hypereutectiod[above .80%C] just because of the carbon content.As far as cryo vs noncryo it depends on the steel AND if they have been heat treated properly.
 
This has been an interesting thread. Thank you all for your restraint :)

FWIW, my favorite steel is the one the customer wants and one that I've did the heat treatment on.

1095, 01, D2, 52100, S125/90/60/30, 3V, ATS34/154CM, 440C, A2, Accuto 440, many different types of damascus, S7, 5160, and others. Took me 32 years to figure it all out and still improving my methods.

The Real test is the customer. Don't need no other Stinkin Tests :)
 
Mike Hull said:
Oh, Im sure a few others realized it right off, but in my case, I figured that pointing out one inaccuracy at a time was enough for now.;) :D
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All I know is, if I had a supplier that sent me A6 when I asked for 440C, or vice versa, I'd be getting a new supplier.
 
Hesparus said:
Personally, I'm very excited about this test. My favorite steel is 5160, but the steel I use on all of my knives is 154cm. I don't think stainless or carbon steels are crap, I'm just really interested to see how the perform side by side. While we're at it, is anyone willing to test a cryo vs non cryo steel?

- Chris
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yeeeees :D well at least for the SS's :) hey you guys, can you tell that I like 154CM :D
I'm with Kit
BUT I will talk some customers into my point of view though more that not. :) .I had one guy that wanted a bronze blade and he wanted it to work.. :rolleyes: . NOT nada no way :barf: needless to say I didn't take that job
my name on it or not that one was not going to happen..

but if the customer wants a reasonable STEEL that is what he'll get but with some recommending..
 
Bronze worked for thousands of years .They were cast of course then the edges were work hardened. And before that there were flint and obsidion knives But they are not metal so I can't talk about those.
 
mete said:
Bronze worked for thousands of years .They were cast of course then the edges were work hardened. And before that there were flint and obsidion knives But they are not metal so I can't talk about those.
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Robert
I believe it had to work back then they didn't have 154CM to work with :D
 
my grandfather was a machinist and a ametuer blacksmith, and he told me the machining company he worked for had cyrotempering done to its machining bits. from what he says its a waste of 4 bucks. but that wasnt knives they had cyrotuned, so i dont think it applys. also they had the bits dipped in liquid nitrogen! nowadays its slowly cooled, (over 3 days usually) with nitrogen flowing around it, but not making contact, so it doesnt cause nearly as much shock, and stress to the steel
 
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