CPM 154 VS 154 CM Is there any difference in these two steels?

RAZORBLADES

RAZORBLADES

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I have one of each of these 110's ,a cpm 154 blade and a 154 cm blade.I'm interested in knowing the differences if any in these two steels.Anyone know anything about them?
 
http://www.bladeforums.com/forums/showthread.php/961889-CPM-154cm-Vs-154-cm

A quote from another forum:

"The Crucible steel 154CM is from the 1970's, it was originally used for jet engine components. Bob Loveless popularized the steel for custom knives but the custom makers used very small quantites of the minimum "heat" for alloy production.

When Crucible dropped the steel in favor of newer jet engine alloys,,,,,Bob Loveless went the Hitachi Metals Div. in CA and described what he wanted,,,,,,Hitachi made up the alloy ATS-34 which was almost identical to 154CM but was cleaner with the new steelmaking equiipment in Japan. Cleaner steel = less impurities.

In the late 1990's Cricuble again became interested in custom steels for the knife industry and introduced CPM 154 with similar alloy content but with a far different process to produce the steel, Crucible Powdered Metal is a cleaner method for small quantities.

Are they the same alloy,,,,,,on paper yes,,,, in the world of metallurgy,,,,,no.
Can the average knife user tell the difference = no."
 
Thanks Plumberdv,I ran a search but never found what i wanted to know,this is what i was looking for,good stuff!
 
Thanks Dave for the quote. Yes, agreed. The CPM-154 is of the powder metalurgy, Crucible's process. Whereas, the 154-CM steel is not. It's of a melt, filter and remelt and filter process. Google for the process, it's an interesting read.This steel of today is of better quality than Japan's process for making ATS-34. Yes, in the 70's there was a problem makers found with the steel (154-CM) and Cruclble later listened and addressed it. Thus, a step up and knife supply houses reflect this better steel in price. The 154-CM steel of today cost me three times that of Japan's ATS-34 as of the last time I purchased some. People want the American the made steel for a reason. Could you tell which was which, if two knives were made of the two steels and you sharpened and used them? I doubt it. Can a maker tell the difference who grinds and heat treats the two steels for a year, working with it? I believe so. There are good articles written on this subject. Robert W. Loveless has since passed but his right hand man lives here in Silver City and we see each other at shows and exchange ideas and history of knife making from this legend. DM
 
Great info,I do know who Bob Loveless is,I have a couple drop point hunters he made years ago,his design was something else for sure!
 
Except that 154CM was not developed by Crucible. And Hitachi did not develop ATS-34 for Bob Loveless. And your timeline is wrong.

154CM was developed by Climax Molybdenum Company (hence the suffix "CM"). It was used for fan blades for jet turbines at one point. Crucible bought the alloy formulation from Climax Molybdenum. Crucible initially had trouble processing it and their batches were inferior to those from Climax. Hitachi did develop ATS-34, but not for Bob Loveless. (Spend megabucks developing an alloy for a single knife maker? No way in Hades is that happening. Bob may have introduced knife makers to Hitachi's alloy, but they would not have developed it for him.) Hitachi did have a purer process and their alloy had less inclusions. Later Crucible perfected their process and by the 90's it was Hitachi who was having problems with inclusions in ATS-34. By early in this century both companies had fixed their problems.

CPM 154 has the same composition as 154CM, but made by a powder metal process instead of a melt alloy process. I don't remember seeing 154CM before maybe 2006 or so. IIRC, it came AFTER S30V, which was still having hiccups in 2006.

I've never tried CPM154, so I cannot say from personal experience, but a number of users whose opinions I trust have posted that they greatly prefer CPM 154 to S30V. They swear it has far superior properties to 154CM. With the finer carbide particles, I would expect that CPM 154 would indeed outperform 154CM.
 
knarfeng said:
Except that 154CM was not developed by Crucible. And Hitachi did not develop ATS-34 for Bob Loveless. And your timeline is wrong.

154CM was developed by Climax Molybdenum Company (hence the suffix "CM"). It was used for fan blades for jet turbines at one point. Crucible bought the alloy formulation from Climax Molybdenum. Crucible initially had trouble processing it and their batches were inferior to those from Climax. Hitachi did develop ATS-34, but not for Bob Loveless. (Spend megabucks developing an alloy for a single knife maker? No way in Hades is that happening. Bob may have introduced knife makers to Hitachi's alloy, but they would not have developed it for him.)
Click to expand...

Well Frank, neither the timeline nor the idea that they (Hitachi) developed the steel for Mr. Loveless are mine. I simply quoted a thread from another source and never vouched for its accuracy. I neither know anything nor do I care anything about the subject, I was simply trying to point the OP to some sources that addressed his question.
 
I realized that you were quoting. I should have been more careful in my phrasing. My apologies for that.
 
Being a compressed powder steel, CPM154 has a granular structure and is more brittle than 154CM. The CPM154 is a great slicer and holds an edge longer than 154CM, and can be polished to a glassy finish. It would make a terrible survival knife though.
 
The opposite is true of powder steel alloys. They are tougher than their ingot produced counterparts, and do not have a granular structure. The chromium carbides are smaller and more evenly distributed in the CPM version, leading to better toughness, and better polishing characteristics. The CPM version will also sharpen to a fine edge easier and will respond to heat treatment more consistently. It's also more expensive.
 
I've really just started taking a technical interest in the new cpm/powder steels in the last month or so. They've been around for nearly 15 years now in knives, starting with S60V in my old Kershaw Random Task. The new ones are pretty nice though, and the 2nd and 3rd generation powder production methods really bring out the best in them. I'm not sure where the brittle thing got started with them. They are in fact brittle, but it has nothing to do with the cpm/powder process used to make them. They are just very highly alloyed steels with a lot of carbide volume and low toughness compared to less complicated alloys with much lower carbide volumes. In fact, were it not for the CPM processes, many of these steels couldn't be made at all.

Because of the higher cost and unnecessarily high wear resistance for my uses, I tend to avoid them. The advantages of the powder processing really are obvious in cases like this where you have CPM 154 and 154 CM to compare directly, though I must admit that I did not find my sole 154 CM blade lacking.
 
Mine neither, the 154-cm stayed close to ATS-34 in most ways and 'normal 440C' there with them. Yes, without powder metallurgy many steels of today would not be possible and many are good steels. All are good slicers/ cutter with fine carbides and sharpen up well. Yet, these are not my 1st choice for a chopper. DM
 
Now with pictures. Both 154 CM and CPM 154 are in the attached micrographs. Notice how small the CPM 154 carbides (the white clear bits) are compared to the 154 CM ones. I'd personally take 13c27, but that's not what we're talking about in this thread.

http://knifetalkonline.com/smf/index.php?topic=350.0

This is Ed Fowler's forum, with pics by Larrin, courtesy of Sandvic from Blade Show a few years ago.
 
Yes, the CPM steels will always look, 1) finer grain structure, 2) grains more evenly dispersed. under magnification. Thus it can be noted, tighter grain structure without voids lends itself to greater strength. With photos much depends on where they were taken and heat treat. Looking at the photos, 154-cm and ATS-34 appear very close with 440C better and D2 a step down the ladder. It depends on what the intended use will be and heat treat as to which steel one chooses. Still, in real world use they are close and people won't normally notice much ( if some a slight) difference. For me I could take any of those steels and use them for a lifetime and be very pleased with their performance and not notice much difference. But I don't chop with a knife. Still, I can't ignore that some of this is influenced by trends and over emphasising marketing and technology. DM
 
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