Just How Good is CPM S30V?

DavidXJ

Member
I really enjoy making my knives out of 5160 steel... it's forgiving and has fairly easy hardening/tempering capabilities for a novice like me that likes to heat treat with a torch and kitchen oven. I like that I can get free 5160 when my buddies or I swap out leaf springs on our Jeeps. Mainly, though, I was astounded at the difference in edge retention and toughness of these 5160 blades when compared to the cheap stainless steel blades I'd been using since childhood. But I HATE that it rusts if you even whisper the word "moisture."

So, I think I would like to try a blade out of one of these new "super steels," like CPM S30V. I'd send it away to do the heat treating, because I don't have the equipment to even attempt it. I've read a lot of opinions about this steel, but I still have two lingering questions no forum or website has ever been able to get rid of:

1. In a performance test (NOT including corrosion resistance), how does CPM S30V compare to 5160?

2. Similarly, from a strictly performance aspect (not including cost, stainlessness, or ease of heat treat), is there still something about a carbon steel like 5160 that would make it preferable to some over CPM S30V?
 
'Performance test' is a pretty broad and subjective term. There is wear resistance and there is toughness and there is strength. Which are you wanting to test?

5160 will be a LOT tougher. S30v will be MUCH more corrosion resistant. Don't know how edge retention will compare. By hearsay and the numbers, S30v should hold an edge longer............however.............

I recently tested a blade of s30v heat treated by a known heat treating professional. I was NOT impressed by it's wear resistance (edge holding) at all. Which surprised me because as you stated, it is touted to be a 'Super Steel'. The edge didn't hold up very well (as far as toughness) compared to some forged carbon steel blades either, which I did expect. It had a whole bunch of small chips in the edge after about 125 cuts through sisal rope.

Advantages of some carbon steels would be better toughness, maybe a little easier to resharpen, still hold a very good edge. Some carbon steels like 80crv2, CPM 3v and CPM d2 are good tough steels that hold a great edge and have fairly decent stain resistance for steels that aren't actually considered 'stainless'.
 
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Hello David and welcome to the pack.
I have only used a few knives made of 5160 and haven't build any using it. On the other hand I have used stainless steels extensively for over 17 years and can tell you that S30V is an excellent steel for its combo of edge holding & stain resistance.

Its tough to work compared to carbon steel and even other stainless steels. It is best to do a brush satin finish on it. I'm sure someone has gotten a mirror finish on S30V? I sure haven't.

It's a top rate powdered metal steel for hard use knives. It does have a sister steel S35VN that is about 20% easier to machine that I actually prefer to use for my culinary and hunters etc. You may want to look at S35VN as well.

There are stainless buyers and there are carbon steel buyers and a few that like both. The 5160 knives I have used were easier to sharpen and the S30V & S35VN hold their edge longer with those big carbide clusters they have.
That's about as much as I can help here.
 
All of my user knives kitchen knives included are now s30v. I have never experienced any other steel with it's ability of edge retention (other than it's cousin s35vn) and there is not a steel I have not tried.
 
Somewhere on this forum one of the guys was saying there is a maker that only uses A2 for his tactical knives. As I recall they said his knives had a very good reputation.
 
Any of you guys that have experience with s30v have any insight as to what happened to the blade I tested? I know I didn't give a ton of info, not sure I want to publicly either.

But I was hoping to test that blade to use as a measuring stick for some of my blades and was very surprised to find it quite lacking in edge holding, and not so surprised to find it quite lacking in toughness.
 
John, that's very odd. Again, without specifics we can't make many firm guesses at what's going on, but I'll also say that the professional "heat treat only" guys aren't infallible. Neither is a particular production batch of a previously great steel. There are so many possible reasons for a blade to comparatively fail against it's expectations. I do have some fairly non-intrusive questions to ask -

Was there only 1 blade which you reviewed that ended up performing poorly? Chasing down others of the batch may be worthwhile.
Also, just for giggles, what was the advertised hardness of the steel?

In my opinion, S30V is excellent. It dosen't have a very smooth cutting edge, but I've found I can minimize that by utilizing finer sharpening abrasives beyond what I would use for 1095. Out of the steels I have made dozens of knives from, I'd say that it is in the lead of edge retention, far ahead of 5160. Does it in my opinion get as sharp as 3V or 1095, no - but it holds the edge for what I feel is longer and is also fully stainless so it's become my go-to steel if stainless is required and I'm not mirror polishing.

My opinion also is entirely muddied up with my variances in edge geometry, the given knives I've built for different tasks, and any bias I've soaked up. Anyone's mileage may vary but I myself recommend it as it works for me and my particular product.
 
Any of you guys that have experience with s30v have any insight as to what happened to the blade I tested? I know I didn't give a ton of info, not sure I want to publicly either.

But I was hoping to test that blade to use as a measuring stick for some of my blades and was very surprised to find it quite lacking in edge holding, and not so surprised to find it quite lacking in toughness.

John,
Like Frank said, without specifics? ??
My guess is that if it was ground or just finished after HT and got too hot? That could be the reason?

I really think you should try it again and do her yourself. The powder metal of CPM-S30V and its sister gives a fine homogenous mix and those large carbides just keep cutting.
 
Thanks for the replies!:smile: It sounds like I would like CPM S30V or S35VN. I'm starting to get a feel for the difference. I apologize for not being moer specific about what part of performance I'm talking about. I'm partial to camp knives... large blade choppers that can cut and also be used to "baton" wood. I would be willing to sacrifice a little edge retention if that means the tip of the blade won't crack off when I beat on it with stick. In my experience, 5160 excels at taking this kind of abuse with a large blade. So that's the type of performance I'm looking to match while adding corrosion resistance.

J. Doyle listed 3 attributes: wear resistance, toughness, and strength. I think, of those three, I value toughness the most.

So maybe that should be my question: Could S35VN or CPM S30V be used on a large camp blade, like 7" - 9"?

These pictures are of a blade I made to take backpacking that gets a lot of pounding to split logs for cooking. This is the type I'm talking about. Forgive me for the camera phone pics... whoever said taking pictures of knives is harder than making them wasn't kidding. The sheath, too, is just poor man's kydex (gray pvc). I haven't put much attention on that side of it yet.
20140605_190657.jpg20140605_190632.jpgEdited Knive.jpg
 
David, Generally, If you want to chop wood & split with a knife, a bit more of a belly really helps. I've use S30V for several large 7-11' choppers and had great results. I had the RC at 57-59 so that it's a little softer. Work fine.
 
Laurence,

Thanks for the info about the RC numbers. :) That will be very helpful to know to make sure I don't make them too brittle to take a beating.

I realize that the full flat grind isn't as good for chopping as a fatter spine with a steeper angle would be, but because this is my backpacking knife, I was trying to get as much weight out of it as possible. That's also the reasoning behind the skeletonized handle with just parachord. It's 1/4" thick, so it splits wood well enough to be a good balance between weight and performance.
 
David,
My large 7-12" camp or what we are referring to as choppers are always a FFG to the top. I am making a knife first with cutting and slicing ability first. If I really want to chop wood that much, I bring a Axe or Hatchet. Do keep in mind that mine are 1 1/2 to 3" in height of blade.
 
How good is any one of the top dozen or so knife making steels?

Good enough that no real world user doing real world knife tasks could distinguish one from the other.

The law of diminishing return comes into play, if there is any real world "return" whatsoever.

As you might guess, I don't sell or market steel or quenchants.
 
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"Good enough that no real world user doing real world knife tasks could distinguish one from the other."

Sir! How DARE you suggest the Emperor has no clothes on.....!! LOL
 
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