Blade Steel - tool steels

[Maas]

Somewhat techincal question for the knife gurus here.

I've worked with A2, D2, M2, CPM 3V - 10V and know applications for Tool & Die , but where does ATS 34 fall in line with these?

Is it a factory name like CPM?

[Bill Harsey]

Good morning Maas, ATS-34 is the chemical equivalent of 154CM. Bit of history here, 154CM is a high grade of bearing steel made by Crucible Steel in Syracuse NY. The story I have is 154CM was first made use as secondary turbine bearings in the 747 engine. This steel was never used for that application but we got some very good stuff for knifemaking out of this. 154CM was made famous as a knife steel by Bob Loveless. Crucible was bought and wrung out by Colt Industries. Price of 154CM skyrocketed so the very well known knifemaker, Bob Loveless went to Japan and had a sit down meeting with the president of Hitachi Steel and asked him if he would make this alloy. Hitachi did and the steel is called ATS-34. This name does not correspond to standard United States steel designations but neither do many United States made steels when given a market use name to sell the steel without disclosing the chemical makeup or standard United States steel alloy designation. The chemical composition of 154CM is the same as ATS-34 but method of rolling into final dimension is differant. ATS-34 is made into long bar stock (this may have changed) and 154CM is cross rolled into sheet form so it can be laser or water jet cut much easier thus lending it to modern factory production. This cross rolling of 154CM results in a more even distribution of carbides resulting in better edge holding. IMPORTANT NOTE HERE: Crucible is and has been for some time an employee owned company. Colt is out of the picture. Crucible is doing a very good job of making sophisticated specialty tool steels at competitive prices. They are the producer of the CPM S-30V used in the Yarborough knife. I have personally used a lot of ATS-34 and never had a problem with it. This steel will even take a higher polish than 154CM and that is a desirable feature to a custom knifemaker for sporting use knives that are around rain and salt water. This is not the finish we would use on any tactical use knife.

[Bill Harsey]

Ok now you guys have done it, since I don't want to get caught being wrong too often, I hiked out to the shop and grabbed some steel references. Since Maas has experience with some pretty exotic steels and I failed to answer part of his question, "where does ATS-34 fit in with his group", I'll try again. ATS-34 has 1.03% carbon, .25% Mangenese, .40% Silicon, 13.75% Chromium and 3.56% Molybdenum. This makes it a fairly straight forward tool steel with the minimum threshold of chromium for stainless steel characteristics. To compare it to D-2: D-2 has 1.50% Carbon, .40% Mangenese, 12.0% Chromium .80% Molybdenum and .90% Vanadium. Here are some important points between the steels, D-2 has more carbon resulting in the possibilty of getting this steel much harder. The Chromium content of D-2 is just under the stainless threshold which means it will have some stain resistance but will stain and rust in bad conditions. The vanadium in D-2 is just enough to aid in grain refinement and heat treat ability (hardening) but not enough to form vanadium carbides. D-2 was designed as a die steel and has a bit too much carbon to have high toughness when sharpened to an acute edge angle. If the knifemaker knows this, D-2 can still make a very good knife. I've also used a lot of D-2 in the past and am mostly happy with it. The only problem I've had is when I heat treat for best edge holding and some user chips the blade doing something really stupid (from my very narrow knifemakers point of view) with the knife, like using a folder to pry apart the hip joint on a bull elk, instead of cutting the connecting tissues. ATS-34 falls below the particle metal steels (CPM's) when it comes to ultimate performance in a knife blade. As knifemakers we measure performance in toughness (pry bar strength), edge holding (hardness of carbides and the steel matrix that holds them) and of high importance, (even to The Reaper except he doesn't know it yet...) is stain resistance. Salt atmosphere can take away the sharpness of a knifes edge without the knife ever being used. Time and humidity can do the same. Hope this helps, Bill

[Team Sergeant]

Thank you Mr. Harsey for writing that in a language we simple laymen can understand! As I was reading I was thinking to myself “this is about to go over my head� but you kept it down-to-earth.

Thanks,

TS

[Maas]

Mr. Harsey,

Thank you for the response. I work everyday with these steels, but I'm no metallurgist. So I also appreciate you keeping it down to earth.

Now I understand why lots of diemakers I know are using D2 to make their knives. I just thought it was because it was the easiest to scarf from the steel rack.

Maas

[Bill Harsey]

Mr. Maas, D-2 is a common tool steel out here in timber country (western Oregon). It is was used by the ton in planer blades that can be identified by the mark "Ohio Knfe Company OK #6" and a splash of green paint on the back. Of course other tool steels are used in both planer and chipper blades but every millwright in Oregon has made planer blade knives from D-2. If I may ask, what type of machine shop do you work in? Sounds interesting. Bill

[Eagle5US]

WOW
Talk about having an assett on the boards! Thank you Mr. Harsey, my education has begun

Eagle

[Maas]

Mr. Harsey,

It's plain ole Maas. I currently work for a large shop in New York. We manufacture Tool & Die components for the stamping industry.

I live in Tennessee and got the job as part of a modified affirmative action program. I'm the only Southerner in a company of New Yawkers. I work the South trouble shooting and teaching classes.