I want to like 52100... but..

Mike Krall said:
Me, I'd rather a specifics driven discussion about modified HT of 52100 maximizing it's knife characteristics than talking about talking about it.

Mike
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i can be with you on that
in kitchen knives and razors all that really matters is that edge and i aim to get all i can from it
 
No offense intended, but how do you know that the 52100 does? Tool steels are used in a much wider scope and subject to the same if not more scrutiny.
 
When I first started testing knives to destruction, I found many faults in steel that was claimed to be subject of tight quality control. This is not to say that any specific steel is not subject to tight quality control but when we as bladesmiths purchase it from dealers, neither we not they can know exactly what they have. It could have come from any steel mill and made at any time and made available on the market. This is not meant to make any claims against anyone - just my observations.

Journeymen smith applicants who have come to my shop to test have brought blades that they purchased from what they knew as reputable sources. When they tested their blade in preparation for the test, the blades failed. Many of their test blades had serious faults in the steel that were probably present when they purchased the steel.

Once I had achieved a reliable source of steel, all from the same pour, many of the variables that had frustrated me were no more. This is the most significant variable that allowed us to develop what we have achieved.

52100 is made and purchased on reputation of quality, when bearings fail it does not take long for folks using them to realize faulty 52100 and the mill looses clients. Again the best may or may not be available on the open market.

In over 30 years of workng with used JD load control shafts I have never found a fault in the steel, they must know what they want and demand quality. I cannot say the same for springs from who knows where. John Deer took care of the quality control issues for us.

I feel that the most significant problem for blade smiths who seek high endurance performance blades is to find a reliable source of their steel. You will never know unless you test blades to destruction. And you cannot be confident in what you sell unless you know all the steel you use is the same as you used for your test blades.

When we know exactly what we are working with, life is a lot easier. This lesson took me years to learn and I offer these thougths for your consideration, you are naturally free to make your own decisions.
 
I think that someone just reading that 52100 has good quality control is not going to infer that it has good QC in the specific batch that you order. I can order 52100 from Admiral Steel just the same as I can O1 or 1075 or whatever. I have no reason to trust more their 52100 more than any other steel that they sell.

O1 is perhaps the most widely used oil hardening tool steel by machine shops. I think that we could agree that O1's reputation also comes from the people using it demanding a quality product.

I don't disagree that it's beneficial to find a source and stick to the same run of steel if you want to squeeze every last bit of performance out of it. I've also only heard of a handful of steels having great variance between melts - 52100 being one of them. I seem to recall you speaking on this in your video, but I can't be sure of my recollection. I have never heard of any serious consistency issues with O1 or any other tool steel.
 
so how do you know what you are buying, how do you know the quality of any steels purchased if the main factor in performance that is not in the makers experience is where the maker gets his steel. I have only ever used 0-1, and A-2 that was already tempered and i just grinded it( back when i first started) who is the source with consistant steel. How can we eliminate the one thing we have no control over-our source and their steel.--marekz--really i havent read everything but who is the man with the reputable steel.
 
marekz said:
so how do you know what you are buying, how do you know the quality of any steels purchased if the main factor in performance that is not in the makers experience is where the maker gets his steel. I have only ever used 0-1, and A-2 that was already tempered and i just grinded it( back when i first started) who is the source with consistant steel. How can we eliminate the one thing we have no control over-our source and their steel.--marekz--really i havent read everything but who is the man with the reputable steel.
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Marekz,

If the seller cannot supply the batch chemistry, there is no way to even tell what steel you are buying.

A person can buy steel without a batch chemistry, but you have to have an established trust with the seller. The quality is controlled by ASTM standards. Level of quality above minimum-required is controlled by the manufacturerer. I said that last because Ed Caffrey has said he quit using 1095 because the batches he was getting had stringers. He did not say all 1095 has stringers, just the batches he has gotten most recently, from where he got it, did. The ASTM standards may have been met, but that 1095 didn't meet his personal finish standards (maybe stuctural too, but I don't know that).

It may be Ed Fowler, in the post 6 up from here, was implying a person needs to use the batch of steel to know whether it works for the worker. He didn't say and I can't speculate. If it doesn't work, it doesn't... but a person is going to have to buy, (as best they can) to find out.

Mike
 
One famous and great maker claimed to us only xxxxxxxx steel, "the best available". Rex shot some chemistry's of some of his blades made at various times, the chemistry varied with the blades. As I remember 6 blades, 6 different chemistry's, no two the same. It turned out that his supplier was a dealer purchasing steel from different outfits according to cost and availability.
Still performance of his blades was very consistent. Why? Because he developed a reliable method of testing his blades and varied his heat treat to match the steel, each batch was treated differently.

If you do not seriously test your blades performance, it does not matter what steel you use for you will never know the difference.
 
Any steel material can be custom ordered to very high cleanliness standards - e.g. double vacuum melted tool steel. Thats a custom order though and I can walk into my aircraft supply shop and purchase aviation certified 52100 with the certification certificate off the shelf. You cant get that in all other tool steel other materials off the shelf.
 
cotdt said:
How does 52100 compare to O1? What are the pros and cons?
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The difference to knife performance is in it's mechanical properties. It all depends on what is desired to be achieved and what compromises can be settled on.
 
I found some technical info between the two steels:

52100 is available from America, while O-1 is not an American product.

O-1 is becoming less and less popular.

52100 rusts very easily, but O-1 rusts even more easily.

52100 has finer carbides than O-1.
 
I'm pretty sure Carpenter, Crucilble, and Latrobe make their own O1 (I would expect others here, also) and I know I've seen large quantity Japanese and European 52100 lot remnants available at Metal Suppliers Online within the past year (with batch specs available which would likely include testing qualifications).

I suppose it could be the large, non-U.S., batches of 52100 could have been purchased then found not to actually meet spec. and are being sold off for best dollar, but I think it's too much of a blanket statement to imply foreign steel is by nature substandard... the Germans and Swedes (and likely, others) would take issue with that.

Mike
 
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I saw some interesting notes about O1 that suggested with cryo treatment, O1 would have better edge retention than D2.

I'd like to see somebody that has cryo capabilities and O1 do a simple test or two between cryo and non cryo O1 blades.
 
Should be Cryo. isn't necessary. That is Cryo. in the method of slow cool to -300F range, hold, slow warm. Tool Steels, 3rd ed. has numerous mentions of "sub zero" treatment of tool steels to eliminate (nearly as possible, is my reading) retained austenite. Alcohol or acetone and dry ice will reach -100 +/- that Tool Steels means when they say "sub zero".

There is a question whether just reaching -100F transforms the austenite to martensite or whether the temp needs a hold. Mete says because martensite forms at the speed of sound, the logic is reaching -100F would take the transformation to MF, or as near to no-retained-austenite as can be reached for the alloy. He didn't say what industry practice is and neither does "Tool Steels", that I can find.

Mike
 
Mike Krall said:
Should be Cryo. isn't necessary. That is Cryo. in the method of slow cool to -300F range, hold, slow warm. Tool Steels, 3rd ed. has numerous mentions of "sub zero" treatment of tool steels to eliminate (nearly as possible, is my reading) retained austenite. Alcohol or acetone and dry ice will reach -100 +/- that Tool Steels means when they say "sub zero".

There is a question whether just reaching -100F transforms the austenite to martensite or whether the temp needs a hold. Mete says because martensite forms at the speed of sound, the logic is reaching -100F would take the transformation to MF, or as near to no-retained-austenite as can be reached for the alloy. He didn't say what industry practice is and neither does "Tool Steels", that I can find.

Mike
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What about putting the O1 into the freezer? Would that reach Mf? It doesn't have many alloys so I'm thinking a really low temperature is not required.
 
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