Any rumors of HT changes?

JustinFournier

JustinFournier

Joined
May 7, 2012
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Anyone heard any rumors about changes to the S35VN HT?

I know Chris stuck to his guns on the current HT. Wondering now if maybe we will see some improvements to it with all the changes around CRK lately.

My favorite pocket knife, my Sebenza 25 w/ micarta inlay completely failed me on a simple task today. The edge lost it's sharpness nearly 2 minutes into cutting some carpet. I actually got a blister I was pushing so hard to try to get it to cut, and this was coming freshly off a strop.

Out of annoyance I grabbed a completely inappropriate knife which was duller, but in 3V with the delta HT protocol, and it embarrassed my Sebenza.

I feel like that guy in a Ferrari who gets destroyed off the line by a Mustang or something.
 
The heat treat was increased a point in 2013 to 59-60. An appropriate knife for carpet cutting is an Olfa knife. $15. The thick blade, and relatively thick edge of the 25 will make the job harder than it needs be. It may simply be the wrong knife for the job, regardless of it's edge holding ability. I have never seen a pro carpet layer using anything resembling a 25 to cut carpet, but understand it's fun to use our expensive pocket knifes for such stuff. The ideal carpet knife does not force the carpet apart (carpet is designed not to stretch), but slices through it, and typically has a sheepsfoot or hawksbill blade.

If you want to use a CRK for carpet, the large 21 Insingo might be a better option. Thinner at the tip, thinner blade, and less aggressive jimping for less blisters.
 
As per posted above, the heattreat has been the same for about 3 years now.
In my experience some of the factory sharpening leaves room for improvement. Added to that sometimes making an edge on a beltgrinder heats te metal just a little too much..... Enough to ruin the ht very locally.
Might be worth a shot to resharpen the blade and check if it'll hold better now......



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I have experienced that the large insingo cuts the best and holds its edge the longest out of all the CRK knives I have owned.

I have cut carpet with my old insingo and it performed better than what you described.
 
Serrations!!!! To me the 25 blade is thicker than I like, and agree the Insingo has that advantage, now, If I could just one with Serrations!!! ( Damascus)!! Then I'd be done!
 
I can't help but think that the carpet being rolled ("nice and tight", and taped) was a contributing factor.
I do understand being disappointed that your 25 didn't handle the job; but, at the same time, it doesn't seem like the right knife for the task.
 
I agree it is not the best knife for the task.

The knife I used to finish it was a .188 thick one, and as I said, it made quick work of it. It was massively inappropriate. 10" long.

I suppose NvG you could have a good idea, I could throw it on the WE and take some metal off and see if it does better.

Edit: This reminds me of the Busse guys saying the INFI does much better after removing the factory edge.

It's not that I wanted to use a Sebenza in particular, it's what I carry all day every day. This is the first time I have ever done this specific cutting task.

While I don't expect the sebenza to be amazing at it, I didn't expect it to fail at is like it did.
 
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I agree that old carpet can be VERY hard on knife edges.

I actually wish that CRK would use normal V edge bevels instead of convexing them. With CRK's awesome primary blade grinds, I feel a good V grind at 20 DPS out of the box would be sharper, hold its edge longer, and be easier to resharpen when needed. IMO, conventional V bevels would also maximize the cutting advantages of CRK's hollow grinds (and possibly the new heat treat) better than the convex bevels.

Then again, I'm a user, not a knifemaker, so these impressions may be right or wrong.

Jim
 
I used a 21 s35vn, Manix 2 s90v , manix cts-bd1 and SNG cpm154. All did about the same. Dulling plenty quick. The 21 and manix cut longer due to tip geometry. I'd never use my beloved ti lock on carpet. Its a waste of a great edge. Id use a razor and a fixed blade. Perhaps my Mora.

Same goes for yellow nylon rope. Super sucks.

^^I also remove the steep convex edge over time. A month in I have a nice 40 degree slight convex edge on any knife.
 
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Sounds like you need to drop $600 on one of them 3V Impofus! 3V is an impressive steel. The only downside is it's not as stain resistant and a bit more of a bear to sharpen.

FYI: the reason old carpet (if that is what you were cutting) is so tough on knives is that carpets accumulate large amounts of sand (anyone who has ever removed carpet will know what I mean). Sand isn't picked up by vacuum cleaners or 'carpet doctor" type rug cleaners. It basically keeps building up until the carpet is replaced. Another factor is some old carpets had asbestos in the carpet substrate weave to make them less flammable. Asbestos will dull a knife in no time.

http://asbestosglobal.org/asbestos-in-carpets/
 
Thanks for the input all.

Carpet was just an Ikea area rug. I am not bashing Ikea here, but the thing cost probably $100 or something, it is about a year old. It's just laying over top of a piece of underlay in my son's room. Well was. I move it to clean when I vacuum every week, so there was no visible sand dirt or anything. Certainly there could be some trapped in there. I'm just saying it was not old 20 year old carpet in a room that was nasty or anything.

I have a bunch of knives with the latest delta protocol HT on the 3V from CPK, Carother's performance knives. It low temp and one of the benefits of which is it leaves enough chromium free so the 3V is almost stainless. I have noticed zero rust, zero staining so far. At this point in time, it is hands down my favorite steel if done with the Delta HT.

I know BRKT uses a a bit higher hardness on the S35VN, so maybe that would have been better.
 
I threw a shoe at a goose earlier today, it just bounced right off of it, out of desperation I grabbed my shotgun and blasted at the goose, and it embarrassed the shoe...
 
I have a small 21 Insingo made within the last two years and it is a great, hard-working cutter. As has been posted, the CRK heat treat has been changed since the end of 2013 to provide a higher hardness. What is the birthdate on your knife's birth card?

Also, the 25 has a thicker blade than the equivalent sized 21. Of course, besides completely different steels with different properties, strengths and weaknesses, the 25 and the CPK knife you used have different edge geometries. I know you know all this impacts a knife's cutting ability and edge retention already, so I guess I don't understand your confusion. That said, if you really meant what you said about your CRK having "the edge retention of aluminum foil", I'd be more than happy to trade your CRK for a Spyderco folder with super steel that should hold an edge a bit longer than your S35VN CRK blade. :)
 
Sorry JF......but this is starting to sound like some underhanded, thinly disguised, advert for these CPK "delta heat treat" knives. If your stoked about them, that's cool, but this sorta thing is kinda cheese-balls at best on the CRK forum.
 
Steel_Addiction said:
I threw a shoe at a goose earlier today, it just bounced right off of it, out of desperation I grabbed my shotgun and blasted at the goose, and it embarrassed the shoe...
Click to expand...

I just want to understand, are you saying using a Sebenza to cut a piece of a newish cheap area rug is the equivalent to throwing a shoe at a goose?

If so, what kind of work exactly do you think a Sebenza is suited for?
 
I was just kidding, :cool:

I've cut rugs, fiberglass insulation, sheetrock with a sebenza 25 myself without any edge issues.

Might have something to do with your initial sharpening? Maybe you had a real thin edge and it got curled over?

I always sharpen on an edgepro and put a microbevel and it leaves a very strong working edge for months.
 
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kidcongo said:
Sorry JF......but this is starting to sound like some underhanded, thinly disguised, advert for these CPK "delta heat treat" knives. If your stoked about them, that's cool, but this sorta thing is kinda cheese-balls at best on the CRK forum.
Click to expand...

I'm trying to separate the 3V, from the delta 3V like the Impofu. Sorry if that is outta place. It's really not the same thing is all I am getting at.

Anyways, back on topic.
 
Steel_Addiction said:
I was just kidding, :cool:

I've cut rugs, fiberglass insulation, sheetrock with a sebenza 25 myself without any edge issues.

Might have something to do with your stropping? Maybe you had a real thin edge and it got curled over?

I always sharpen on an edgepro and put a microbevel and it leaves a very strong working edge for months.
Click to expand...

Yeah, maybe the edge was too thin. I can't feel any curls on it or anything. It feels relatively smooth, nothing like big chips. It feels like the edge is just gone.

Maybe I need to go to the WE then, what geometry are you using exactly?
 
In my experience the Sebenza's with the new heat treat can handle 30 degrees inclusive very well.
 
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