About fed up with my CPM-154 steel

G

godogs57

Joined
Apr 16, 2004
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This is the second go-round with CPM-154 and, again, I am seeing pits and inclusions along the blade that only appear on the final polish. This is specifically the reason I got away from ATS-34 was because of the inclusions!

It always follows the same process: following heat treat, I take it down to 800 grit, polish with two grades of Matchless green and then Matchless white. Only after everything is completed do I have an "oh crap" moment. Pits in the ricasso...pits in he hollow grind....

At this point I either trash the blade or sand down to 400 grit satin finish and just not sell it. This is infuriating!

Note in the attached picture what I'm talking about in the upper part of the ricasso:

20140907_180815.jpg
 
Yes I have talked with Crucible about this and they replaced the "bad" steel. This blade is from the replacement steel. It's getting old to see this happen on two out of every three blades I make from this stuff. It's enough to make me want to go back to plain ol 440C.
 
No, the CPM process doesn't prevent this. I see this sort of thing in CPM M4, CPM 3V and CPM 154.

It's a fair bit more difficult to work with and spendy and less popular with buyers, but Elmax is super clean and is a phenomenal steel. I've never noticed an inclusion in it ever and it polishes without the orange peal you see in 440C

Some of those Sandvik steels are supposed to be very clean.
 
What would be the major differences in Elmax over CPM154? I have never used Elmax but have used quite a bit of CPM154. I too have seen some inclusions in the CPM154.

Nathan the Machinist said:
No, the CPM process doesn't prevent this. I see this sort of thing in CPM M4, CPM 3V and CPM 154.

It's a fair bit more difficult to work with and spendy and less popular with buyers, but Elmax is super clean and is a phenomenal steel. I've never noticed an inclusion in it ever and it polishes without the orange peal you see in 440C

Some of those Sandvik steels are supposed to be very clean.
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M390 is much the same as Elmax. They are very good steels for edge holding and fine finishing. They are a little more time consuming to work. They are not often available in thinner sizes that is under .140 On the other hand ABL-E made by the same company is almost too easy to work finishes super too and will take an extra fine edge that's way easier to sharpen than Elmax or M390. Frank
 
^ABL-E is pretty awesome for fine edge stability but it don't have much abrasion resistance. It is a relatively low carbon steel.
 
MJV said:
What would be the major differences in Elmax over CPM154? I have never used Elmax but have used quite a bit of CPM154. I too have seen some inclusions in the CPM154.
Click to expand...

Elmax is very high carbon with 3% vanadium. You'd think it would be brittle but it's tough as hell. 154 is easier to sharpen.

Elmax is 3rd gen powder. CPM 154 is 1st gen. Elmax starts out as a fine dust, CPM is like coarse sugar.

In practice I think the folks making Elmax just do a better job of keeping their work clean and consistent. It mirror polishes without flaw. I see flaws in CPM steel pretty frequently.
 
Oh... I was just going to buy a bunch of cpm154 or 154cm.

I forgot about the inclusion problems going on of late.

I was at a knife show and a guy attending the show pulled out a beautiful hunter he had made and was heart broken when the problem showed up in the last steps of the blade.
 
FWIW, If I use stainless I prefer Elmax for all the same reasons Nathan gave. It is super easy to work until it is hardened so be sure most all the heavy stock removal is done before heat treat.
 
They didn't include the word "Microclean" in the name for M390 for nothing. Its good stuff, I actually prefer it over ELMAX unless I'm making a SS knife that needs more toughness than M390 provides. They're both excellent steels and IMHO about the cleanest stuff available.
 
I, too, would like to try Elmax. I used M390 but gave up on it because I couldn't find it in reasonable thicknesses any more. Does anyone know where I can find Elmax and M390 in .125?

Tim
 
Elmax is my current favorite "stainless" steel by far. Remarkably tough stuff, even when compared to "carbon" steels. In fact, that's where it really shines - overall toughness.

I had a couple friends of mine who are very used to 1095CV, beat the living snot out an Elmax blade I built (very thin edge, HT by Peters, Rc58), and they were frankly stunned at how well it held up. Pounding it directly through knots in red oak, stuff like that.

My Elmax test-blade flat-out smoked Ka-Bar's 1095CV (which ain't exactly terrible) in rough, tough bushcrafty/survivalist kinds of testing... it didn't chip at the edge, it didn't break, the tip didn't snap off, and it didn't get dull. The last guy who tested it flat refused to send it back to me... he paid me full price and kept it for himself. To my mind, that's a pretty powerful testimonial.

Elmax exhibits truly outstanding edge-stability under pretty damn severe testing at what I consider a moderate hardness (58Rc). Despite the high carbide content, it's not nearly as hard to re-sharp as you might think, because you can grind it thin in the first place without being afraid of it falling appart.

My only problem with Elmax is availability and cost. I sincerely hope it gets rolled out in more sizes so I can use it more.

I hear similar encouraging things about M390... but again... it's a little difficult to wrap my hands around and make a decent-size batch.

CPM-154 is my "standard", "stainless" steel. It kicks much behind performance-wise/compared to cost. Yes, I have found tiny inclusions in it, too... and I agree, that's a problem. If you're making an art piece, what's coming out of Crucible today may not be pretty enough. If you're making working blades,,, the stuff just plain works. *shrug*
 
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This is the problem I see with a lot of the super stainless knives. I want a thin knife, not a .140"+ knife. Any ideas where to get Elmax in sub .125" ranges? I can't find thin M390 either. Found CPM-20CV at usaknifemaker, which is basically the same, but I'd like to try Elmax.
 
I just contacted someone the other day slipped my memory who it was, but they replied that they did not carry Elmax anymore, and they could not tell me who did.
 
I buy it direct from Uddeholm. Obviously they're not going to want to sell you a single bar, but their sheet size is about 24X36 so it's not exactly a lifetime supply either.

It's a bear to saw.

It is rolled out in an austenitic can that has to be ground/milled off.
 
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