PM2 in M390 vs PM2 in CTS-204p

[TennToadsticker]

I've heard a lot about how similar CTS-204p is to M390, but having read way too many steel threads it seems as if the steel gurus will point out that the relative performance of these blades "is as much or more about the heat treat" as anything else. I think the HT of the blue M390 is about 62, but has anyone heard if the green CTS-204p will be any higher? Thanks for any information on this.

[michaelm466]

There's no info about target hardness at spyderco or the dealer, however since they are nearly the same steel I don't see any evidence that would make me think they would run these harder or softer than the M390, I expect these will basically be like the S90V vs 20CP (carpenter's version of S90V) PM2's of which one can not tell a performance difference between the two in use or most tests (I remember one test where 20cp showed very slightly less flat spots on the edge in a comparison test, although that could have easily been due to the variation in material being cut.

[marthinus]

There are a lot more factors the just the Rockwell hardness.

Running the steel at a higher hardness can decrease its corrosion resistance, increase brittleness and decrease toughness.

The higher the quality control during heat treat the more accurate heat treat process will be done. The soaking that takes place as well as the anealling of the steel is just as important.

Also...even batches of the same steel can give slightly different performance with the same heat treating process.

Both steels should perform the same nun the less given that the quality of heat treat is the same.

[spydusse]

There is no way spyderco is running their m390 at 62. If they did it would easily out preform s90 and cts20cp they run at 60. M390 is not brittle at 62 as i have a south fork run this hard by phil wilson

[TennToadsticker]

I stand corrected, Spydusse. After your post I went back and checked the note I got from Bento Box Shop when I asked them about it and they said "In terms of hardness, Spyderco did not provide this information. However, based on tests from end user on the M390 Mule Team, it's approximately 61."

[kreole]

I stand corrected, Spydusse. After your post I went back and checked the note I got from Bento Box Shop when I asked them about it and they said "In terms of hardness, Spyderco did not provide this information. However, based on tests from end user on the M390 Mule Team, it's approximately 61."

The thread on the Mule shows they went for 59-60 with most testing there, some testing at 61 http://www.spyderco.com/forums/showthread.php?49823-Spyderco-Mule-Team-MT11P-M390

[Ankerson]

There is no way spyderco is running their m390 at 62. If they did it would easily out preform s90 and cts20cp they run at 60. M390 is not brittle at 62 as i have a south fork run this hard by phil wilson

Correct, the Mule I tested came in at 60.5 HRC.

And no way M390 is brittle at 62 HRC as you said I tested a few of Phil's knives at 62, one that was .005" behind the edge and own a Smoke Creek in M390 that's 62.

[TennToadsticker]

Has Phil Wilson or anyone else tested the upper limits of M390 to see how far it can go (in terms of heat treat) before becoming too brittle for general use?

[Ankerson]

Has Phil Wilson or anyone else tested the upper limits of M390 to see how far it can go (in terms of heat treat) before becoming too brittle for general use?

I know of one of his knives in M390 at 63 HRC and it was still not brittle.

[TennToadsticker]

I bet it was one heckuva cutting machine.

[Ankerson]

I bet it was one heckuva cutting machine.

I know the person that owns it and yeah he really likes it a lot, and it gets used all the time.

[TennToadsticker]

He probably hasn't had to sharpen it yet, either.

On a related note, I'd be very interested to see a chart developed someday that shows changes in toughness and edge retention for extraordinary steels like M390, S90V, S110V, etc. with each HT point increase from 59 up to 63 and beyond.

[Ankerson]

He probably hasn't had to sharpen it yet, either.

On a related note, I'd be very interested to see a chart developed someday that shows changes in toughness and edge retention for extraordinary steels like M390, S90V, S110V, etc. with each HT point increase from 59 up to 63 and beyond.

That data is available on the Crucible data sheets for their steels.

[TennToadsticker]

Great. I'll check it out. The big question is whether or not I'll be able to make sense of it. Thanks.

[Chipped Karambit]

I've heard a lot about how similar CTS-204p is to M390, but having read way too many steel threads it seems as if the steel gurus will point out that the relative performance of these blades "is as much or more about the heat treat" as anything else. I think the HT of the blue M390 is about 62, but has anyone heard if the green CTS-204p will be any higher? Thanks for any information on this.

it is not at 62. I have it in my pocket now. More around 59 or 60. 62 is optimal that only midtechs or customs can do easily.