RSK : S30V (chipping defect)

I seems everyone is having the problem with S30V chipping a lot. This is kind of funny though. Crusible is trying to say that this is super steel with super tough character design specially for cutterly., with the cooperation with Chris Reef.

From the content in the steel, also could be possible that they are having a good alloy contents, high Molib and Vanadium, which is required for good tool steel grade.

The manufacturing technology is also great, with the atomizer to make the steel content uniform across the blade. This wil also make the steel grain size small for higher strength.

But the outcome is not as expected by many people. It chip badly. I also suspect that there are 2 possibilities, the heat treat and the steel itself.

Since many manufacturers encounter the same problem, I would say the steel might be the problematic issue and amplified by the heat treat problem.

I am not a metalergist, but that is just my thought here.
 
It seems to be a hit or miss thing. My brother noted a little chipping with his mini-RSK, but I have not seen any chipping on my mini-RSK, even using a jeweler's loupe. I have used it on cardboard, and for vigorous whittling of dry pine and dry apple.
 
BG42 is a great steel but it is very difficult to heat treat because of specific requirements for how to do it. From what I understand it is also difficult to make this steel. It has something to do with how clean it is due to the double vacuum smelting process involved in making it but right now I fail to remember all the details on it. Senior moment I guess. :D

Basically it boils down to expense. It is much cheaper to use ATS34 or 154CM than to go the extra to get BG42 up and running. Thats primarily why you only see BG42 in limited run knives most of the time I think.

STR
 
my MT Scarab has performed great. mind u i haven't hacked away at stuff, but i have cut plastic parts off vehicles, and wire with. no chipping, but i did blunt the edge when i cut the wire. i was able to sharpen it out after a little work on the stone.

my Camillus Dominator has performed quite well too. it too cut through wire, and hemp plants. held it's edge very well and did not exhibit any chipping. it has worked hard and was my first real exposure to S30V.

i have a MT MTX2 that is my current EDC. no problems yet.

it's been my experience that i like to have a more 'toothy' edge with S30V. when i mirror polish the edge, S30V doesn't perfrom as well as for me. but maybe it's just me. i don't really test knives...
 
I had a Dominator that I used quite hard, and I had no problem with the S30V. I have had problems with the RSK and Manix (one, but not the second).

It's so strange that the problems are both widespread, but sporatic. Most people seem to have no problems, but a large minority do.

My guess is that S30V is a very good knife steel, but something is going wrong during the manufacturing process. I hesitate to buy another S30V knife until the makers figure out what's going on and learn to avoid the problems.
 
proguide said:
Cliff, the test you did on the manix and para a wile back seemed to provide better results. Is it the way these two companies process their steel?
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It has to be, I doubt they are getting different runs and I reprofiles edges so they are the same angle, the difference is in how they are heat treated.

Steelhed said:
I have several knives in S30V, including an RSK, and I have not experienced any chipping problems so far. I have used my large Sebenza in S30V extensively, including extended work at reducing large cardboard boxes to strips and I have not seen any chipping.
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You have to go very low in angle to have a knife chip out on cardboard, my small Sebenza chipped on cardboard when the blade was sharpened essentially flat to the stone, so much less than 10 degrees per side.

stjames said:
What was the Rockwell Hardness of the RSK? How about that of the paramilitary? And the Skirmish you also mentioned?
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None of them were individually HRC tested, the factory spec's are 58/60 for the RSK, I assume the same for the Skirmish, Spyderco's are 58/59, same as my small Sebenza :

http://www.bladeforums.com/forums/showpost.php?p=2032715&postcount=6

There are many ways to get to the same hardness though, quench medium, cold treatment and soak temperature can all change the internals at the same hardness.

Barrabas said:
I am curious to ask if it is your conclusion at this point, is that S30V itself is the issue, or if it is all leading back to the heat treatment on these that is causing the chipping.
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It is hard to determine the optimal performance because the materials data isn't provided from Crucible and the makers/manufacturers rarely describe their heat treating. As a user you can just go by what you are given. This thread however is just staggering in regards to number of problems especially given that S30V was promoted based on its toughness.

Considering your tests on S30V to date, would it be worth it to try to do a test on a Strider - or is there not enough treatment difference to warrant that in comparison to the others you have tested?
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Additional info is always of benefit. I'd repeat the work with additional samples of the same blade if I had them.

BG-42 is basically a high speed stainless steel, it has a high soak temperature, 2050 F and very high tempers. On paper it looks like a very nice cutting stainless steel, but that austenizing temperature isn't going to be attractive for some.



-Cliff
 
have a benchmade 440 oportunist with s30v-havent cut anything yet
also have a dominator that has been my edc for a few weeks,i cut box's with tiles and marble inside,blade gets used very hard and hasnt had any problems-

maybe camillus knows the secret way to temper it-
 
Cliff, maybe you should pick up an Cabela's Buck 110, it has a S30V blade Bos treated. It would be pretty much the same steel as a Strider (if nowhere near the thickness).
 
It seems like it would be an interesting experiment to re-heat treat one of the blades used in the tests where they had chipping problems and then repeat the test.

-john
 
Cliff:

As always, our RSKs are covered by our unconditional guarantee. Feel free to send the knife back and we will replace it or return you money--your choice.

Brent Blue
Aeromdix.com
 
I have several knives in the S30V and when I had chipping problems it was with a polished edge. Since I like a toothy edge I no longer use the finer stones. Just finish off with the 600 grit DMT stone (red). Have not had any more problems. I have also had some chipping problems with 154 and VG10 when the edges were polished. Maybe the finer edge has something to do with it and then again maybe it is something else that is causing the problem.Never hurts to get rid of the factory edge right out of the box and start over either.
 
I don't know if I've just been lucky, or if I'm just not running my edges fine enough to see the problem pop up. I've got 3 S30V folders, a Spydie Yojimbo and two BMs, an Ares and a Switchback. I got the 921 used and I've EDC'd the hell out of the Ares and Yojimbo - no chipping that I've noticed. I usually finish on a 1200 grit DMT flat stone and strop just enough to evaporate the burr, if at all.

The Benchmades seem to be harder - they certainly have significantly better edge holding than the Yojimbo.
 
Brent Blue/Aeromedix said:
Feel free to send the knife back and we will replace it or return you money--your choice.
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As noted this isn't my knife, it is also a replacement for another RSK which was defective in the same manner.

-Cliff
 
No luck for me. I bought Native and use it in office. I cut some plastic bags, cardboard boxes and when I feel it is getting dull, I tried to resharpen it on Sharpmaker and it start to chip. More I sharpen Native was getting duller and duller. May be it was chipping before sharpening, I do not know, I was not aware of this problem, and I did not look at the edge with a loupe.
Then, I return it and got a new about a week ago.
Yesterday I was using first time, cut a tape, and four hollow plastic pins about ¼” in diameter.
Later at night, I was reading this thread and decided to inspect Native’s edge with 10X loupe and I found that blade is chipping. Today I put this knife on microscope with about 40 magnifications. That is bad. No luck for me with S30V for now. I will return Native and will stay away from S30V for now. Most likely get Native 3. I really like shape of these knives.
R
 
You may want to try giving the edge a full sharpening, for some this has solved the chipping problem.

-Cliff
 
When you give it that full sharpening service lay the blade almost flat on a good bench stone if you have one and remove the factory edge. Watch the bevel so you can keep it even on both sides. After you have done this then you can go to the secondary bevel somewhere between 15 and 20 deg. depending on the type of edge you want. If the heat treat is ok and it probably is you should wind up with a pretty good working edge depending on what grit of stones you use. That is pretty much the way I was taught to do it and it does work. You may find that doing it over a couple of day works better than trying to do it all at once. Some blades work better at different bevels than the standard 15 & 20 that so many rave about.
 
Wow, Scary thread....The only knives of mine that see chipping during normal cutting are during inital post-HT testing, and the chipping reveals that the knife has not achieved the right tempering to pass the brass rod test (where the entire length of a blade edge is pressed against a brass rod and must visibly be able to flex and rebound without chipping or deforming the blade)I am no expert on high end fancy steels, but with carbon, if the edge chips out during normal use, you messed up the HT. From what I read, it seems to be the norm for this type of steel, but that doesnt make much sense. I'd much prefer a steel that dulled faster but did not actually chip out...anyone ever look into these chips to see if their fractures create more microscopic cracking along the edge, worsening the problem?
 
I have a Manix and a Native in S30V and have noticed no chippping and I use the Native extensively. I also use a Lansky and reprofiled it to 25 degrees. Cliff has made some excellent points on edge thickness and sharpening. I noticed that the Native had small chips on the edge when I purchased it from Walmart used it for a few days until it dulled and then sharpened it at 25 degrees with the Lansky and have no problems since. I also polish my edges if this has an effect. Thanks.:D
 
TikTock said:
...anyone ever look into these chips to see if their fractures create more microscopic cracking along the edge...
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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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