RSK : S30V (chipping defect)

There are a lot of reports of people finding S30V blades hard to sharpen, many assume it is just due to the low machinability, however I wonder how many cases could have been due to to similar behavior. Unless the user checked under magnification it would have been very frustrating because the blade literally just refuses to respond and if anything gets duller when you move to finer abrasives.

-Cliff
 
Cliff Stamp said:
On the two Benchmades (Skirmish / RSK) that I handled, the chipping would happen readily during sharpening and during use it would cause the edge to break apart rapidly, the edge holding was very low because the steel cracked off and this was with fairly obtuse edge angles ~15 degrees per side.

-Cliff
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Cliff, Maybe you can help us by putting the review for the Skirmish. That would be interesting to see what kind of test you did with the knife until you see the chipping.
 
I didn't review the knife, I was just checking it as the user was having problems getting it sharp. I checked it under magnification and it broke apart under the flats of the Sharpmaker hones. Edge retention issues were similar as to the RSK, pretty much none as it would break apart it use on just light cutting.

-Cliff
 
Something must be wrong if the edge was chipping/breaking while being sharpened.

My mini RSK did exhibit minor chipping while cutting dry Hickory and cardboard (in one sitting) with the factory edge. By minor I mean the chips were just barely visible at 20X magnification. My Buck Mayo did not show this behavior on the same Hickory and cardboard. But even so, the observed edge retention was very similar with these two knives. Both knives sharpened back up quite sharp very easily.
 
It's kind of funny when you think about it. When people make knives out of steels designed for other jobs or out of tool steel the steel works great.

When you make knives out of a steel developed specifically for knives it works worse.

That just doesn't make sense to me.

Now it makes me not want to buy a new 940 with S30V. That stinks pretty bad. Maybe I should just get one in 154CM.
 
It is unlikely that S30V was developed just for personal cutlery, though some have promoted it for this in the past, the data sheets and in general information from Crucible tend to say otherwise :

http://www.bladeforums.com/forums/showpost.php?p=3117662&postcount=42

Several other steels have been promoted as specific cutlery steels, it doesn't really matter though what something was designed for as much as how it actually works for that purpose. M2 makes a nice fine cutting knife, though designed originally for high hot hardness.

-Cliff
 
I've had an RSK for awhile, moderate use, resharpened it with an EdgePro Apex, same angles as factory, and had no problems with chipping. Just got a mini-RSK, haven't used it much or resharpened it, but no indications of chipping so far.

Just lucky? Or not pushing the blades enough to see the defects?
 
I just picked up a Native at a Super Walmart in a North Denver suburb (Spyderco's back yard, assuming they face south). I *really* like this knife, the Native 3d is one of my favorites, this one is a little thinner in the handle, and I love the black clip, much more subtle in the office than a wire clip.

I'll post a report on how the S30V holds up, first I want to profile this and the VG10 model exactly the same with my edgepro.
 
Cliff Stamp said:
You may want to try giving the edge a full sharpening, for some this has solved the chipping problem.

-Cliff
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Cliff, thank you for advice. It is worked. I remove some steel from primary bevel on 30 degrees settings. It took over 200 strokes on medium Sharpmaker’s stones to form a burr, than few strokes on flats. After that I reset stones to 40 degrees and went through normal sharpening process. Blade does not have chipping anymore, and it sharp that I can shave, at least for now. I will try to use it a lot to see if blade will chip or not.
Thank you very much for help.
Roman
 
I have these knives in S30V:

Manix, Chinook, Native, Sebenza and the RSK. They've all seemed fine, except for the Native -the blade chips out when sharpening (sharpened several times now) and edge retention isn't brilliant, but it's okay. I have a mini Pika in 440C that has better retention. The other knives are all fine. Maybe it's the batch of steel or since it's a new process they're still trying to work the bugs out. Dunno?
 
Sal no, but I don't think it is hardness specifically, I have used harder knives and knives which are definately more brittle, I have for example M2 at 65 HRC which is brittle by any standards but doesn't behave like the S30V Benchmades which chipped during sharpening.

There are many possible reasons for it which include possibly oversoaking, carbide precipitation during quenching, too long before tempering after quenching, or issues like lack of multiple tempers if the secondary hardening peak is used, and of course overheating during sharpening.

The real puzzle is that this one both chipped and deformed readily which is an odd combination, and it is the first time I can remember that a blade went blunt on the arkansas stone. I sharpened a Paramilitary and UK Pen it with no problems so it isn't an intrinsic steel issue.

sodak said:
I'll post a report on how the S30V holds up...
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Looking forward to it.

-Cliff
 
Hi all,

So, what would be the latest on this chipping issue? I recently got an RSK from another BF member, and have been thinking about getting another as a user/backup...

I'm a knife newbie and am not sure what chipping would look like to the naked eye, but I did use the RSK (well, my roommate) in a way that produced a 3mm long flat-looking part to the edge - he pushed the tip into a very hard piece of plastic packaging and then pushed straight down w/ no sawing motion...is this just regular blade dulling? I had hoped the edge would hold an edge visibly undulled longer than one push...but perhaps this is just normal?

thanks guys
 
might have had a wire edge that broke off. Chipping will look like you might expect, tiny chips (or larger if you're real unlucky) of the edge missing
 
By way of some follow-up. I have two RSK's, my first one came in S30V and the second is the M2 bladed version. I am looking at the S30V one as I write and I cannot find any evidence of chipping, and I have carried it all over the country for awhile now. The M2 version has a nice little chip in the middle of the blade edge, approximately .5 millimeter long and deep (nice little semi-circle. So go figure, the version that is suppose to be problematic in the chip area has not given me any problems, while the M2 version has chipped out, although I think I did it while cutting around bottle trying to open one of those new fangled plastic safety thingys.
 
Neat, thanks for the responses. Steelhed, did you sharpen either blade at all? Too bad about your M2 - I've been looking for one of those, given the touted strengths of the M2. How would you take care of a chip like that, just sharpen it away?

Hardheart - a wire edge, is that just a more pronounced burr, or a very thin extrusion of the blade edge? I don't know if it matters but it happened on the untouched factory edge.
 
mcmc said:
So, what would be the latest on this chipping issue?
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Problems seem to have decreased, mainly due to people who were seeing them moving to other steels.

... in a way that produced a 3mm long flat-looking part to the edge - he pushed the tip into a very hard piece of plastic packaging and then pushed straight down w/ no sawing motion...is this just regular blade dulling?
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No it is defective. Often however just the steel along the edge is so damaged for a variety of reasons. Completely sharpen the knife removing all damage and repeat the cutting. If it continues get the knife replaced.

-Cliff
 
Larrin said:
I've never seen any reports of sales of S30V knives decreasing.
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Was there a large reduction in reported problems with liner locks awhile after Mike, and later Steve and Joe's comments were origionally posted/discussed and supported by other users - yes. There was an initial large flood as many people posted support but after awhile this died down and now there is almost no discussion or commentary in that regard. Did the locks actually get better - no. Discriminating users simply looked elsewhere or relegated liner locks to less demanding use. However did this cause a large drop in the sales of liner locks - no. Does this mean that Joe, Steve, Mike and others didn't point out a significant and inherent problem - no.

Even if the defect rate on S30V was insanely high like 25% (it likely isn't even close to this), if you factored in the effect of the percentage of discriminating users, then the percentage who wrote off the steel, then the reduced amount they buy (users don't tend to buy the same volumes as collectors, and serious users even less so) it would be obvious that the total volume of sales would not be adversely effected. You really can't use popularity to argue performance in either direction, if you did you would have to accept that 420 stainless is the best cutlery steel.

Plus would you really expect manufacturers to actually make public statements about the popularity of their designs/steels being reduced anyway. Unless you have some kind of independent ability to audit their records you are essentially letting salesmens give you information on the popularity of their product.

-Cliff
 
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