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Posted By: 8888 steels - 12/31/09
Can anyone tell me if cmp154 and 154cm are the same steels. I cant seem to get an answer on the internet. Thanks
Posted By: 1234567 Re: steels - 12/31/09
They both have the same element content, but the way they are manufactured is different.

CPM stands for Crucible Powder Metology (sp?).

From what I have read, but never tried, CPM 154CM is the better steel. Better in that it is stronger and holds an edge better.

There are also other CPM steels; CPM S30V, CPM S90V, and a few others. Google Crucible and they explain Powder Meterology much better than I can.

From what I can find out, CPM 154 CM is no longer available.
Posted By: Journeyman Re: steels - 12/31/09
Though Crucuble was real quiet about the particulars it's printed in quite a few places that CPM 154 does have a hint (0.40-ish) of Vanadium for grain refinement.
Posted By: 1234567 Re: steels - 01/01/10
I have read that, too.

A few minutes ago, I went to the Crucible site and CPM 154 CM is not listed.

Several years ago, I had some ATS 34 analyzed and it showed a trace of Vanidium.
Posted By: 8888 Re: steels - 01/01/10
Thank you Gentlemen and Happy Newyear to you all.
Posted By: michiganroadkill Re: steels - 01/01/10
The future of 154CM and CPM 154 lies in the hands of the new owner/operator of what was Crucible's Mill. There was some info shared on this here on an earlier thread ---part of the "reorganization" of Crucible.
It is my understanding that the CPM process starts with more uniform and smaller particulate size and therefore ends up a more uniform product. Can the user actually see/feel/tell the difference in the field???---I don't think so. But that is just my opinion from using both.
JMHO
Tim
Posted By: djpaintless Re: steels - 01/01/10
Usually the CPM steels seem to be excellent. The only problem I've ever had with any of them was in a knife with CPM D2. It rusted and pitted faster than any other pocket knife I've ever carried.........................DJ
Posted By: Journeyman Re: steels - 01/01/10
Crucible's PM shop is back up and running, but I'm not sure of the products/quantities they're producing/shipping. Even if they don't pull it out, however, if the market's there the steel will be produced. ERASTEEL, Latrobe and Carpenter are all producing excellent vacuum melt and PM steels, both their own and Crucible's. BG 42 and RWL 34 are examples are some of the great knife steels of all time IMO.
Posted By: michiganroadkill Re: steels - 01/01/10
Yeah, I have recently been thinking that I should give BG 42 a look. It sounds like and excellent blade steel.
Posted By: Journeyman Re: steels - 01/01/10
Quote
Usually the CPM steels seem to be excellent. The only problem I've ever had with any of them was in a knife with CPM D2. It rusted and pitted faster than any other pocket knife I've ever carried.........................DJ



I received a knife last week in Carpenter CTS-XHP. Sorta/kinda CPM D2 with 16.00 Chromium. Will be testing it over the next few weeks, but the composition makes it look like a primo corrosion resistant pocket knife steel...
Posted By: Journeyman Re: steels - 01/01/10
Tim, if you decide to, let me know. If I'm in the State's I'd love to heat treat a couple of your blades for you to test. The heat treat hobby's turned into a 1200 SF playshop.
Posted By: 1234567 Re: steels - 01/01/10
MRK, do you know if CPM 154 CM is available now?

I read some reports of it on another site, and the people who have been using it claim that it produces a brilliant shine for mirror polishing.

They also claim, because of the Powder Met., and the fine grain size and the suspected Vanidium content, that it gets scary sharp, sharper than most of the other steels.

BG-42 also got good ratings for ability to get sharp and stay that way.

Contrary to what some might think, grain size and other factors determine just how sharp a knife can be sharpened to. Steels containing Vanadium appear to be in that class that get really sharp, the sharpest of any other steels.

Even the best sharpening method, and the most skilled sharpener can only get the blade as sharp as the steel will take an edge, and some steels seem to do that better than others.

A long time ago, I read that the addition of Platinum would give steel this superior sharpness, but I have never known of a steel company that manufacturers steel containing Platinum.

RWL 34 sounds good, too, but I have never seen a source for it.
Posted By: michiganroadkill Re: steels - 01/01/10
1234567
Ref 154CM and CPM154:
Last I knew there was none around. I am going to need to get some steel in a couple months or less, so will have to find some or try something new to me.
Probably the best info would come by calling Crucible and seeing what they have to say.
Again (JMHO), I doubt that in side by side normal use anyone could actually tell the difference --all else being the same.

Journeyman
So you have worked with BG 42 ???
Tim
Posted By: VAnimrod Re: steels - 01/01/10
I haven't worked with BG-42, but I do have a Lucas Burnley "Sparrow" in BG-42.

Stays sharp a good long time, and is harder than woodpecker lips when it comes time to sharpen. I have noticed that it wants to "polish" sharpen with a smooth edge and slide past stuff as it cuts vs the much toothier edges you get with D2 or 1095.
Posted By: 1234567 Re: steels - 01/01/10
"Again (JMHO), I doubt that in side by side normal use anyone could actually tell the difference --all else being the same."

I have never used CPM 154 CM, but I have made several hundred blades from 154 CM and ATS 34.

From what information I can get on the web, the people who have used both and have made blades from both CPM 154 CM and 154 CM, claim there is a lot of difference, both in the way it grinds, polishes, and also the sharpness and strength.

From what little I know, this bit of extra performance is because of the way the CPM is made, resulting in finer grain structure and a more even mixture of the elements it is made from.

My next choice would be BG 42 if CPM 154 was not available, or else RWL 34.

Posted By: Journeyman Re: steels - 01/01/10
Quote
Journeyman
So you have worked with BG 42 ???
Tim


Yeah, but I'm just an enthusiastic hobbyist - no Phil Wilson or Paul Bos. My original oven was supposedly 2200*, but would vary 40* or more. I have 2 great 2250* units now and am playing with pretty much all of the common knife steels. I kind of blame(credit?) BG42 for that because I like it so much and needed to be able to austenitize at 2050* for 15 - 30 minutes.

Anyway, what I've been doing is buying various steels and having them waterjet cut to a utility design similar to a Wusthoff parer. I then have a "name" bladesmith who does the primary grinds and I treat and finish them up. They're still ugly but really allow me to test the different variables to my heart's content. Not for everyone, but I really enjoy it.

Posted By: seamount Re: steels - 01/02/10
Gentlemen, Last contact I had with Scott Devanna who was at Crucible but is now at Niagara is that a new melt of CPM 154 would be available right about now. CPM 154 is very different from 154Cm even though the chemistry is pretty close. The CPM process makes a very small grain size as has already been stated here. As a result toughness is improved. 154CM is a border line oil quench steel and tends to be a little sluggish in heat treat response, especially with an air quench. It works best at RC 61 but it is hard to get it there. CPM 154 acts different-- added Vanadium or maybe Nitrogen-- I don't really know but it heat treats very nice. No problem at all to get 63/64 as quenched and then temper back to 61. I especially like it for fillet knives since even at 61 it still has good toughness for a flexible blade. Corrosion resistance is fine even around salt water. I have made a few hunters also with CPM 154 and pushed the hardness up to 63. Still adequate toughness for a slicer type skinner for use in the field. These 63 blades with a thin edge cut like crazy and beat CPM D2 in my cutting tests.. Phil
Posted By: 1234567 Re: steels - 01/03/10
Thanks. Usefull information.

Do you cyro quench?
Posted By: elim Re: steels - 01/03/10
Phil how do you sharpen your blades?I was of the super high polish school until Krein convinced me a toothy edge might be better.I sharpen out to 600 and then strop on a hard leather.The cpm154 really seems to like this and I just started playing with a S60v knife.
Posted By: seamount Re: steels - 01/03/10
Gentlemen, I do a cryo quench pretty much as standard procedure. Into the LN2 as soon as the blade comes down to room temp. An option is to do multiple tempers at the high end (950 to 1000). According to some good metallurgists I know this will resolve the retained austentite almost to the same degree as the sub zero.
Elim. I like to use a Silicon Carbide medium or fine grit stone-- Like Norton. I use Windex for lube and that makes it easy to clean the stone. Use the India side to remove the wire edge and then a couple of strokes on a leather strop. Makes a nice aggressive edge that lasts a long time. I find a polished very fine edge rolls to quickly and then you are done.. Phil
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