ATS-34 VS 440C

C

carbonsteelfan

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May 29, 2014
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After collecting about a half a dozen old Spyderco folders in ATS-34 and a Chicago and Cat model in 440c , l have gotten intrigued about these these two old school steels. I have a few questions which l would love your learned input on :
1) Between ATS-34 and 440c , which invariably holds the better edge ? ( Assuming all other factors like blade grinds and hardness are equal )
2 ) which is tougher ? ( As in , stronger for cutting without chipping )
3) Which one takes a keener edge ?
I heard That 440c has large carbides which means that the edges are toothy.
Mr. Sal Glesser , once said that at edge thickness of .004 , 440c carbides cause the edges to break. I also heard that ATS-34 has finer grain structure so it can be ground thinner .
I appreciate your help :)
 
"Invariably" is not a word I would use in any discussion of steel. There are way too many variables in play on blade steels. ATS-34 with a proper heat treat is wonderful. Get the heat treatment wrong and it is worthless. 440C doesn't seem to be quite as finicky, but I personally don't like it quite as well.
 
Damn, had to to check the date on this post lol this was all anyone argued about when talking about knife steels in the mid to late 90's
What funny is that they are really about the same. Small differences yea but it's not like S30v compared to m390 kinda stuff.
 
I for some reason thought ats34 was similar to 440c with manganese added or something.
 
The steel 154CM was initially developed by Crucible Metals for aircraft jet engine components.
Bob Loveless made it very popular for custom knives and it was his favorite steel.
A few years later it was discontinued when the jet engine manuf. evolved to other steels.
Loveless had connections with Hitachi Metals in CA and ordered a run of ATS-34 from Japan which was at that time almost identical to 154CM. ATS-34 became widely available and many knife manuf. ordered the steel from Hitachi.

Regards,
FK
 
That's interesting. I didn't know 154CM was used as an aircraft engine steel. Talk about a tough use, very high heat and centrifugal forces, much more extreme than any knife use I can think of.
 
Steel was being used for the fins on the jet engines. The fins would get hot and expand to hit the housing. Crucible added 4% Moly to stop "high temperature creep". When Boeing went to Ti for fns, Crucible changed the spec of the steel. That's when Hitachi came in with ATS-34 to serve the market for blade steels. When Hitachi ran into some issues, Crucible powdered their 154 to improve the performance.

sal
 
Mr.
Sal Glesser said:
Steel was being used for the fins on the jet engines. The fins would get hot and expand to hit the housing. Crucible added 4% Moly to stop "high temperature creep". When Boeing went to Ti for fns, Crucible changed the spec of the steel. That's when Hitachi came in with ATS-34 to serve the market for blade steels. When Hitachi ran into some issues, Crucible powdered their 154 to improve the performance.

sal
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Mr .Glesser , sir could you please tell me which steel ( 440c or ATS-34 ) takes a keener ( finer ) edge ? And which one has better edge retention according to your research ?
 
GatorFlash1 said:
That's interesting. I didn't know 154CM was used as an aircraft engine steel. Talk about a tough use, very high heat and centrifugal forces, much more extreme than any knife use I can think of.
Click to expand...

In all fairness the steel was probably tempered and treated completely different for that role, no need for edge retention unless you catch a goose with the engine. Still it is very impressive.

I wonder if i could speed up the process of cooking chopped up poultry by throwing birds through a running jet engine.
 
Bird strikes are a serious problem with aircraft.
Interesting side story.
When the Eurorail trains were being designed for 220+ mph, the engineers learned that Boeing was testing the aircraft windscreens with a custom air gun that shot grocery store chickens at the test aircraft.
The train designers arranged to borrow the special gun to test on trains and had a serious problem.
The first shot went through the windscreen and the drivers chair,, ended up in the rear compartment.
They immediately contact Boeing for help.
Answer from Boeing = First thaw the frozen chickens.

Regards,
FK
 
Sal Glesser said:
Steel was being used for the fins on the jet engines. The fins would get hot and expand to hit the housing. Crucible added 4% Moly to stop "high temperature creep". When Boeing went to Ti for fns, Crucible changed the spec of the steel. That's when Hitachi came in with ATS-34 to serve the market for blade steels. When Hitachi ran into some issues, Crucible powdered their 154 to improve the performance.

sal
Click to expand...
Thanks for the information. I like learning about modern knife history.
 
Sal Glesser said:
Steel was being used for the fins on the jet engines. The fins would get hot and expand to hit the housing. Crucible added 4% Moly to stop "high temperature creep". When Boeing went to Ti for fns, Crucible changed the spec of the steel. That's when Hitachi came in with ATS-34 to serve the market for blade steels. When Hitachi ran into some issues, Crucible powdered their 154 to improve the performance.

sal
Click to expand...
double post
 
"Mr .Glesser , sir could you please tell me which steel ( 440c or ATS-34 ) takes a keener ( finer ) edge ? And which one has better edge retention according to your research ?"

I can't speak for Sal or anybody else but I have some experience with these steels.

IMO, 154cm and ATS 34 do take better edges than 440c. Yes, they are also tougher when done for cutlery the way we usually see them. They do have somewhat better grain structures but not as much as the steel when done with powder processing. CPM 154/RWL 34 keep the wear resistance and improve the edge stability and toughness pretty noticeably and are worth whatever price increase they require. Good stuff.

BG 42 is the same steel but with added Vanadium for even greater wear resistance.

IMO, because lots of knife makers use a steel it doesn't mean the steel makes superior knives. 440C steel is inferior in many ways to many steels less used by custom makers from a users standpoint. From their standpoint it has a lot going for it especially for less used art knives that look pretty and should stay that way ( great corrosion resistance). For hard use most modern steel we see is better in more than one way but also costs more, is harder to grind and finish to similar standards, and sometimes more complicated or more time consuming and involved to heat treat. These factors will insure plenty of knifemakers use and recommend 440C to customers for the foreseeable future. I for sure see no advantage to knife users in 440C though.

Joe
 
Thank you sir :)
The Mastiff said:
"Mr .Glesser , sir could you please tell me which steel ( 440c or ATS-34 ) takes a keener ( finer ) edge ? And which one has better edge retention according to your research ?"

I can't speak for Sal or anybody else but I have some experience with these steels.

IMO, 154cm and ATS 34 do take better edges than 440c. Yes, they are also tougher when done for cutlery the way we usually see them. They do have somewhat better grain structures but not as much as the steel when done with powder processing. CPM 154/RWL 34 keep the wear resistance and improve the edge stability and toughness pretty noticeably and are worth whatever price increase they require. Good stuff.

BG 42 is the same steel but with added Vanadium for even greater wear resistance.

IMO, because lots of knife makers use a steel it doesn't mean the steel makes superior knives. 440C steel is inferior in many ways to many steels less used by custom makers from a users standpoint. From their standpoint it has a lot going for it especially for less used art knives that look pretty and should stay that way ( great corrosion resistance). For hard use most modern steel we see is better in more than one way but also costs more, is harder to grind and finish to similar standards, and sometimes more complicated or more time consuming and involved to heat treat. These factors will insure plenty of knifemakers use and recommend 440C to customers for the foreseeable future. I for sure see no advantage to knife users in 440C though.

Joe
Click to expand...
 
Just speaking from my own experience with 440C (some older Benchmade models like the Axis TSEK and early Griptilians, and the Spyderco Meerkat), it doesn't hold an edge as well as ATS-34, but 440C has superior corrosion resistance. 440C does take a good edge, and is a snap to resharpen (not that properly-heat treated ATS-34 is all that difficult to touch up).

Jim
 
We've had better abrasion resistance with 154/ATS than 440C. As mentioned, 440C has better corrosion resistance.

sal
 
Hey , one more question. I hear from some other knife users that ATS-34 blades can be brittle and susceptible to chipping. Is there any truth in this statement , Sal
 
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