S30v Trouble

S

sc00ts

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Apr 13, 2015
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Hi all. I have a pm2 in s30v that I bought from bladehq just over a year ago. I've really struggled sharpening this thing. I've read that s30v will lose accuse sharpness quickly but overall retain a high level of sharpness for quite some time.

I will get this knife to slice newsprint being careful not to leave a burr or wire edge and within a week of light use I can't even cut cardboard with it. It will literally tear through it rather than cut. Yesterday I was trimming juniper bushes at my parents house and used the pm2 on a couple of small branches, maybe as thick as a #2 pencil and the blade completely rolled over.

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I thought s30v was more prone to chipping than rolling, am I just mistaken?

I sharpen on the sharpmaker, 30° back bevel
With 40° micro bevel. I also have a delica in vg-10 that in comparison seems to have far higher edge retention, though I know that's not the case.

Can you help me figure out
A) What I'm doing wrong sharpening this steel?
B) Is what you see in the pics typical of s30v?


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Difficult to say. I haven't had any problems with chipping on my S30V blades (Mini-Rukus, Buck Custom Shop 112), but cardboard will dull just about any steel. S30V is a challenge to sharpen, though, due to the high vanadium carbide content. Diamond hones are about the only hones that work on S30V, and getting the burr off takes a while in my experience. You could try using an angle guide to re-establish the bevel you want and go from there. I doubt there would be any problem with the steel itself as Spyderco has an excellent reputation. You could send it back to Spyderco for evaluation and re-sharpening.
 
I find the Spyderco S30V to be slightly better then the good old VG10 and my finding is the VG10 will roll and S30V likes to chip at 10~13 degrees per side but at 15 dps it is quite robust.
I have sharpened many PM2 in S30V and I find that the factory edge react to the stones as "soft" until I get the factory bevel out and then the sound changes and it feels nice and hard.
So with that I think the edge heat treat was lost some what at factory when they grind the edge, it's done by a robot but on a dry stone that spins at speed (don't know how fast it's turning but enough to create high enough heat)


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The edge looks pretty thick, i.e., at a fairly wide angle. Also appears somewhat rounded in the bevels. If the Sharpmaker (with just the ceramic rods) has been the only tool used to sharpen it, it might be in need of rebevelling; maybe done at a narrower angle as well.

I've been down this road with such a blade (Spyderco S30V); ceramics will only go so far with S30V, after which the edge will start looking more burnished and rounded over, as I mentioned above. Past a limited amount of touchups to a factory edge, it'll eventually need something more aggressive to cut the steel cleanly and reshape the edge to crispness once again. The diamond hones recommended earlier will do it, and much more effectively. I recommend narrowing the edge angle, so the cutting geometry will work better overall. A wide-angled edge used to cut wood will need a lot more force applied, to make the cut. I'm betting that's why (in part, anyway) the edge has been damaged in the first place. Juniper doesn't prune or cut easily anyway, especially if it's dead & dry.


David
 
In my experience this rolling is typical of S30V: There was constant micro-rolling on this $2K RJ Martin Raven even at fairly thick edge angles of well over 15 degrees per side, and 2 years of cold sharpening never got out of any "soft" zone...: See the nail shavings here after 5 chops into Maple: The damage would occur in 1-3 chops...:

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I observed the exact same thing with a 1K custom in CPM 154, and there is a well-discussed case of shockingly easy rolling/distortion with S35VN on a Sebenza, while test-cutting rope: I think the tester's name was JRDavis882. This one started a huge uproar, yet there were confirmed other cases of S35VN failures in other brands...

My feeling is to just avoid CPM steels for knives... And they are hard to sharpen while they do this, and no they don't chip, they just roll like that's what they were made to do...

I guess they do well at some tasks, or they are finicky to get right... Personally I have seen so many similar rolling failures, I would never trust these 3 steels at the very least...


Gaston
 
Very few reports of rolling that I can find. Many reports of chipping, a problem with edge retention. Lots of anecdotes, apples and oranges. Little science. Some really good companies think they have it solved as of several years ago, but here is one of them in the OP. ???

I have never had chipping or rolling with S30V, but then I never chop with a folder and only have folders in S30V.

I also never get a burr except by accidental failure.
 
Ok, thank you everyone for the help, I really appreciate the input. I do have the spyderco diamond stones and will try steepening the back bevel angle.


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I've never had a $0.50 butter knife chip or roll, but I've only used them to spread butter. (anecdotal evidence)

My non stainless blades with twice the vanadium content of s30v are a lot easier to de-burr. They have much better edge stability (resistance to chip and/or roll), take much finer edges off a given stone, and keep their edge longer before the need for sharpening. This applies to all the S*V steels.

It wouldn't bother me if S*V steels just went away, for cutlery use.
 
My Benchmade s30v is no different. Definitely not a fan of this steel.
 
I do not love s30v. Too bad it is so prolific. I have had exactly 0 success with sharpmaker diamond hones. The edge seems to just bounce off the little bumps on it.
 
jll346 said:
My Benchmade s30v is no different. Definitely not a fan of this steel.
Click to expand...

I feel the same way. Glad to know I'm not the only one. I wish I could get a pm2 in vg10 or even 1095!


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I have several Buck knives with S30V steel and use them. I have not experienced what has been expressed here. For me it has been a good steel in pruning, rope cutting and processing. Try to apex it better. DM
 
That edge damage look like it was caused from contacting something very hard. The type of damage you have there would be considered compressive deformation, I see no evidence of chipping and that is way beyond rolling.

I would start by cutting into the stone to grind the edge flat and remove the chips, then reset the apex on a coarse stone.

My experience will S30V in general has been poor, every maker seems to heat treat it in their own way and this puts the steels performance all over the place. Spyderco S30V is middle of the road in terms of HT IMO, good but I have noticed microchipping and have never been impressed with its edge retention to sharpening difficulty ratio.
 
I too have had my share of troubles with S30V blade steel and there aren't many blade steels that Spyderco has used throughout the years that I just don't like for whatever reason. But I've had chipping problems with some of the S30V models that I've owned over the years. So since that all occurred I've gravitated away from any Spyderco model made with S30V blade steel. Personally I like VG-10 much, much better than I ever did S30V.

I'm actually a fan of several of the blade steels that Crucible makes. But S30V is not one of them. I never could get it to hold an edge anywhere near as long as I can with several of my VG-10 models. Had they made the Spyderco Chokwe model in another steel I would have bought one in a heartbeat. My Spyderco Dodo model is one of the few that I've kept and used over the years that has S30V blade steel. But if they would ever bring back that model with a better blade steel I would probably get rid of the two that I own and go with a newer, improved model with better steel.

It's really kind of ironic too because I can remember the seminar that they had at the 2002 Blade Show where several knifemakers were touting it big time. Chris Reeve and the late Rob Siminich were two that come to mind. The company was really proud of it and all the knife magazines were singing it's praises but to me it's sort of been a let down IMO. I actually like it's predecessor 440V better myself.
 
I'm with David Martin on this one.

I don't have a lot of experience with usage, but my Buck s30v is nice stuff.
 
HeavyHanded said:
I'm with David Martin on this one.

I don't have a lot of experience with usage, but my Buck s30v is nice stuff.
Click to expand...

OK now I'm wondering if S30V has the same issue as D-2 does? In other words I'm wondering now if S30V is a tough one to heat treat and maybe the Buck knife company has found a better heat treatment for it? Because I've heard over the years to heat treat D-2 you really have to be sharp like custom knife maker Bob Dozier has obviously found a good heat treatment for it.

Even though I don't buy many Buck products anymore I still have a great deal of respect for the company overall. I think they've been great at heat treating all the way back to the early 70s when I got my very first Buck knife. Even back then it was hard to sharpen one of their knives with an Arkansas Stone. So I'm wondering now if heat treatment or a certain type of quenching is more the issue?
 
I would believe in my case with Benchmade that they know proper heat-treat?? Myself personally, will never buy another S30V knife.
 
do 21 deg and see how that does. also not sure i would use a sharpmaker for this, but thats just me. i like the sharpmaker for touch ups, not much else.

i just sharpened my S30v skyline, it took forever to reprofile it. but its plenty sharp now, just need to test it in the field, i did go around 15deg tho, so im not expecting the world from it. its more of a light use knife anyways.

the damage looks like it was chopped, rather than anything else, but only the OP knows.
 
For the last few months, my ht focus is mainly on stainless steels (12+% free Cr after ht). IME with S30V- its grain is larger than other PM steels, so it can be weak & brittle at the same time. Even with grain refined ht, it's still resulted with larger damage than S90V on the same test (whittle cow or lamb rib bone). CWF HT v1.2 S30V (15 dps, 0.01"BET) performance linearly drop along with hardness (64,63,62,61,60) on this test. Benchmade 940 S30V 60rc (15dps) did very poorly(mondo chip) on this same test.

S35VN is an improved S30V, it added cocktail of elements to refine grain. It's much better than S30V (in std ht). My data - Std ht S35VN edge stability is superior std ht S90V but sub par to CWF HT S90V. For perspective, blade made from steels with Cr 4-5% and C 1.4-3.4%(yes includes rex121 & cpm 15V) out perform S*V blade on the same test.

In whittle African Blackwood test (edge geometry 15dps, 0.01" BET - behind edge thick, DMT E finished):
BM 940(60rc S30V) - failed.
std ht by me S30V (60-63rc) - failed.
std ht by me S35VN - passed (60-62rc), failed(63+rc).
cwf ht 1.2 S30V (60-64rc) - passed.
cwf ht 1.2 S35VN (60-64rc) - passed.
cwf ht 1.2 aebl - passed (62+rc), failed (edge rolled at 61- rc)
cwf ht 1.2 S90V,20CV,S110V,Elmax,CTS-XHP 64+rc - passed.

**** Critically looking at it
We refer/call stainless/stainresistant mostly because cr passivation/oxidation grit is mostly sufficient to cover expose reactive surfaces. Free cr (before passivation) are suspended among matrix martensite crystal blocks (plus grain & carbide boundaries). 'Suspended/Situated' because free Cr is floating (consider a very weak bond if you like) in web of magnetic fields. Matrix consists mainly of transitional metallic bond, which is weaker than covalent bond. When free Cr exceed certain % (I am guessing 10+%) threshold, whence matrix lattice stair-step (steep) loss of cohesion - translated to lower strength + toughness.

**** bottom line for me
Traded some toughness for stain-resistant: Selected candidates S90V, aebl and maybe 1 or 2 mid C% steels.

**** for OP
Sharpen with diamond plates equivalent to DMT C;F;E. S30V with a clean apex is more than serviceable for pressure-cut materials softer than African Blackwood. Use thicker edge geometry for tasks requires higher impact & lateral load. If you want a decent long lasting edge with apex width less than 1.5um, don't use steels with carbide bigger than 1um - yep, S30V isn't it!
 
Exact same experience as others - my Buck Vantage Pro with Bos Heat Treated S30V has been fantastic and is my standard for a beautiful hard use steel. Unfortunately I cannot say the same about my Benchmade 943 in S30V. I have no trouble sharpening/honing either with my Shapton Glass stones; have never had to resort to diamond.
 
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