cpm s30v hardness?

R

rms51

Joined
Jan 11, 2010
Messages
56
i have read that optimal hardness for s30v is rc 58-60. the crk nr worrior is at 55-57. what are the benefits of this? is it less brittle? cr is about the only one i see making s30v at 55-57, why?
 
Have no clue why they would run it so low, performance would be less by doing so. If their trying to gain toughness it would be better to just use a different steel.
 
Performance and hardness are not proportional. A softer steel doesn't necessarily mean an inferior one.
Chris Reeve was one of the guiding minds behind the inception of this steel. His technical and metallurgical insights are the reason that S30V steel exists to begin with.
He's forgotten more about that steel than most of us will ever know about it. If he chooses to run it at 55-57 rockwell, I would trust it.
 
Just because you lower the RC doesn't mean you improve the toughness. Even if it did, now with the lower RC its performance will be that of a lesser steel. I see no point in having such a steel if you never get its maxium performance, its a high wear resistant steel and when you lower its hardness you take away from this value greatly.
 
Originally posted by 3Guardsmen
Does that include the steel's optimal hardness?
Click to expand...

It might. Who knows. The only CRK fixed blade I own is an A2 one-piece, which I trust implicitly despite the Noss tests, which have gone much further than they ought to.
It's fair enough to say the S30V fixed blades do seem unusually soft, but what do I know? The only complaints I have ever heard in my life have been from the Noss destruction tests, which I don't wish to draw attention to. Most of the people who actually own and use the 55-57 Rc S30V fixed blades have been extremely satisfied.
 
I recall in one thread here that the actual hardness of a S30V Sebbie was 59 HRC.
 
I'm not putting anybody down for choosing to run S30V lower that what to me is optimal hardness. I prefer S30V to be run RC60-61

think Paul Bos said in an interview somewhere that the optimal hardness for edgeholding for S30V is 57-58RC
Click to expand...

Are you sure he wasn't talking about toughness? It doesn't make a lot of sense. There are 3 factors that affect the wear resistance of a steel.1) hardness, 2)Type of carbides present. Vanadium being the hardest, Tungsten and Moly are next, Then chrome, etc. 3) overall carbide fraction: The higher the fraction the more wear resistant the steel typically is.

There are quite a few producers of knives that don't push the steel for one or more of 4 reasons typically.

1) extra toughness. They don't want to read about their knives chipping here on the forums

2) easier ( for their end users) to sharpen at lower RC's ( meaning less wear resistance also unfortunately)

3) The harder and more wear resistant a steel is, the more time consuming and costly it is to produce.

4) Some steels have different corrosion values with different heat treat cycles, and different RC's.

Some steels are very different at higher hardness. Without exaggeration try to find some M2 at RC58 ( common with benchmades) , then try it at RC 65-66

Likewise S30V at 57-58 and RC 61

BG42 at RC 58, and RC 62, D2 at RC 57 and RC 62, etc., etc.

It is my opinion however, that knifemakers like Chris Reeve know what their customer base likes and gives it to them.
 
Keep in mind the point by Dan Farr, that the need for blade toughness is commensurate with blade size. With a folder you can't generate the same energy as with a larger knife. Reeve is using S30V in relatively large blades, so that might be the rationale for using a lower hardness.
 
The general trend is that most steels lose toughness as hardness increases. That being said, optimal hardness really depends on how the blade is going to be used. On a larger knife, a slightly softer but tougher blade is prefered since the knife will likely be used for tasks such as batoning or heavy chopping. On a smaller blade, like the ones found in folders, the hardness can be increased since most folders will not see that kind of use.

Although hardness is not the only factor affecting ease of sharpening, it does play a roll. Generally, a slightly softer blade will be easier to maintain in the field. I believe this is why CRK chooses RC 55-57 in their A2 one-peice line. A2 has about the same toughness at RC 57 as it does at RC 60. However, it should sharpen up faster at RC 57 compared to RC 60.

Here is Crucible's A2 data sheet:

http://www.crucibleservice.com/datash/dsA2v12.pdf?CFID=752487&CFTOKEN=93169517
 
The Mastiff said:
I'm not putting anybody down for choosing to run S30V lower that what to me is optimal hardness. I prefer S30V to be run RC60-61



Are you sure he wasn't talking about toughness? It doesn't make a lot of sense. There are 3 factors that affect the wear resistance of a steel.1) hardness, 2)Type of carbides present. Vanadium being the hardest, Tungsten and Moly are next, Then chrome, etc. 3) overall carbide fraction: The higher the fraction the more wear resistant the steel typically is.

There are quite a few producers of knives that don't push the steel for one or more of 4 reasons typically.

1) extra toughness. They don't want to read about their knives chipping here on the forums

2) easier ( for their end users) to sharpen at lower RC's ( meaning less wear resistance also unfortunately)

3) The harder and more wear resistant a steel is, the more time consuming and costly it is to produce.

4) Some steels have different corrosion values with different heat treat cycles, and different RC's.

Some steels are very different at higher hardness. Without exaggeration try to find some M2 at RC58 ( common with benchmades) , then try it at RC 65-66

Likewise S30V at 57-58 and RC 61

BG42 at RC 58, and RC 62, D2 at RC 57 and RC 62, etc., etc.

It is my opinion however, that knifemakers like Chris Reeve know what their customer base likes and gives it to them.
Click to expand...

I thought the same thing, I think it was in an interview with Blade magazine possibly. it might be that going above 57-59 doesn't really increase edge holding enough to warrant the decrease in toughness.
 
The later Sebenza S30V's were 58-59 rc so isn't this a moot point? At this hardness it is still relatively tough. Optimal hardness? I think it's pretty high up there but since very few people have handled S30V blades at very high hardnesses there won't be much consensus.
 
misterjuiceman said:
I think Paul Bos said in an interview somewhere that the optimal hardness for edgeholding for S30V is 57-58RC.
Click to expand...

Paul Bos targets 59.5 for S30V. I had him do a heat treat on my small Sebenza blade because the CR heat treat resulted in a blade that was not even in the same league as my other S30V blades.
 
You must log in or register to reply here.
Back
Top