Heat treat question

[SEALman799]

Hey guys,

So I recently acquired a Sebenza 25 and I absolutely love it. I was a little let down on the edge retention and how sharp I could get the blade (using a spyderco sharpmaker). I believe I feel this way because I was mostly carrying an SMF in CPM 154.

My question is does anyone know if it's possible to retreat the blade? I know CR treats the blades on the softer side, but I've read about some custom makers who've been heat treating the S35VN to a higher RC (in the mid 60s) with awesome results.

Thanks!

Evan

 

[Ankerson]

What are you cutting with it?

When I tested mine I cut over 2200 ft of cardboard, made a bunch of cuts through power cord and whittled wood with it and it still sliced phone book paper.

That was all without touching the edge.

 

[SEALman799]

Mostly 3/4" flex, some 16 gauge wire and cardboard.

Maybe I should just get a better sharpening system?

I'm mostly just curious on if anyone had ever thought of it, I've just heard good things about the harder RCs.

 

[Ankerson]

Mostly 3/4" flex, some 16 gauge wire and cardboard.

Maybe I should just get a better sharpening system?

I'm mostly just curious on if anyone had ever thought of it, I've just heard good things about the harder RCs.

They do a good job with S35VN in the 25.

One would have to do a lot of cutting to see the difference between 59-60 and 61-62.

Might be a sharpening thing though, sounds like it to me.

 

[cujobob]

The Sharpmaker is a good system, but I would think it's a sharpening issue. CPM 154 is generally easier to get a good edge on.

 

[gull wing]

Don't know if it will help, but I find CRK's edge angle too steep for the things I cut.
I reprofile my new CRKs with an Edge Pro to a lower angle* and get great results. Then after that all I need to maintain edge is the Sharpmaker.

* Green level.

 

[SEALman799]

Thanks for the feedback guys, maybe I should just send it in for a spa treatment. I did buy it as a user, and it had been sharpened before. Maybe I should try and sharpen the back bevel?

 

[MatthewSB]

So I recently acquired a Sebenza 25 and I absolutely love it. I was a little let down on the edge retention and how sharp I could get the blade (using a spyderco sharpmaker). I believe I feel this way because I was mostly carrying an SMF in CPM 154.

Strider's CPM154 (and S30V) is like no one else's. They use a proprietary heat treat, and some kind of magic, to get the best stainless I've ever used. Comparing it to CRK, or anyone, is bound to lead to disappointment.

Sebenzas work well because all of the design and build features work together. The softer steel stays sharp and is quick to sharpen because of the convex edge. I was much happier with my CRKs when I gave up on the sharpmaker (which won't even work if whoever ground your blade did it even slightly too obtuse) and went low-tech with sandpaper on a computer mousepad. It takes seconds to get a hair popping edge, which is stronger (resists chipping and rolling bigtime) because of the extra support of the convex edge.

Edited to Add:

I said that Strider's stainless is like no others; I take it back. Spartan Blades proprietary heat treat on their S35VN makes equally incredible steel. I've done a lot of cutting with CRKs, Striders, and Spartans and the Spartan S35VN is just incredible, it's right up there with Strider's S30V and CPM154 and maybe better, in my opinion.

 

[TTTis]

I get all my sebenzas rehardened to 60 by Paul Bos Heat Treat, big difference. I find that is a perfect number for this steel personally.
Stock HT is just way too soft for me. I don't have any chipping issues at the higher hardness and no more edge flattening.

People always claimed nothing was wrong at 58-59, but CRK mid 2013 bumped it up to 59-60. They certainly don't make a change
for no reason. Going to have to pick up a post change CRK and compare to my hardened blades.

 

[SEALman799]

I get all my sebenzas rehardened to 60 by Paul Bos Heat Treat, big difference. I find that is a perfect number for this steel personally.
Stock HT is just way too soft for me. I don't have any chipping issues at the higher hardness and no more edge flattening.

People always claimed nothing was wrong at 58-59, but CRK mid 2013 bumped it up to 59-60. They certainly don't make a change
for no reason. Going to have to pick up a post change CRK and compare to my hardened blades.

I just checked CRK website and it's saying they harden all the folders to 58-59, so i'm not sure if that means they tried it and then switched back or what. Can you give me some info for Paul? I'd like to send mine in for a treat, I'm more of a fan of the harder steel.

 

[Corytr]

I get all my sebenzas rehardened to 60 by Paul Bos Heat Treat, big difference. I find that is a perfect number for this steel personally.
Stock HT is just way too soft for me. I don't have any chipping issues at the higher hardness and no more edge flattening.

People always claimed nothing was wrong at 58-59, but CRK mid 2013 bumped it up to 59-60. They certainly don't make a change
for no reason. Going to have to pick up a post change CRK and compare to my hardened blades.

Very interesting. If you do pick up a "post change" CRK, please let us know you opinions on the comparison.

 

[WyattCooper]

I just checked CRK website and it's saying they harden all the folders to 58-59, so i'm not sure if that means they tried it and then switched back or what. Can you give me some info for Paul? I'd like to send mine in for a treat, I'm more of a fan of the harder steel.

They haven't updated the website.

 

[rishma]

Why do birth cards still say 58-59? That seems like a significant oversight.

 

[Ankerson]

Had one of my old Zaans hardness tested, that's S30V.... 2011 BD.

Came in at 59.5 HRC.

FYI...

 

[bhyde]

Had one of my old Zaans hardness tested, that's S30V.... 2011 BD.

Came in at 59.5 HRC.

FYI...

Reworking the heat treat for 1-2 more points of hardness seems to be overkill for the gain. Not knowing what the current hardness is and then proceeding down the path seems borderline madness or OCD.

I think I would rather spend the money from gaining this extra hardness on 1) spa treatments every few years OR 2) A new blade when the time comes..

 

[Ankerson]

Reworking the heat treat for 1-2 more points of hardness seems to be overkill for the gain. Not knowing what the current hardness is and then proceeding down the path seems borderline madness or OCD.

I think I would rather spend the money from gaining this extra hardness on 1) spa treatments every few years OR 2) A new blade when the time comes..

That came like that from CRK at that hardness.

I don't have blades redone.

 

[TTTis]

I just checked CRK website and it's saying they harden all the folders to 58-59, so i'm not sure if that means they tried it and then switched back or what. Can you give me some info for Paul? I'd like to send mine in for a treat, I'm more of a fan of the harder steel.

Google Paul Bos Heat Treating.... everything you need.

They haven't updated the website.

Correct.

Had one of my old Zaans hardness tested, that's S30V.... 2011 BD.

Came in at 59.5 HRC.

FYI...

They definitely exist. My two S35's were tested at 57.5 & 58.5. If mine was 59.5 from the factory, that would be perfect. Given the sebenza is the only knife I carry... I'm excited for the bump in hardness.

Reworking the heat treat for 1-2 more points of hardness seems to be overkill for the gain. Not knowing what the current hardness is and then proceeding down the path seems borderline madness or OCD.

I think I would rather spend the money from gaining this extra hardness on 1) spa treatments every few years OR 2) A new blade when the time comes..

Lol, come on now. We are talking about 20 bucks here. You spend 400 on a knife, but 20 for a harder blade is too much? In my experience 1-2 points can make a huge difference.

Plus the hardness is checked before and after re-hardening so you aren't going in "not knowing". I'd always tell paul if it's 59.5 before, then just send it back. Don't mind paying 20 to find out. Worth it for a knife I'm going to carry for years and years.

 

[bhyde]

That came like that from CRK at that hardness.

I don't have blades redone.

You misunderstood my my intention,..I apologize..I quoted you because of your proximity to 60hrc..
It's so close, that I don't think even the most advanced user could tell the difference from 59 to 60hrc..I am not even sure about the calibration of such equipment to that fine, I would have to ask the materials scientists that work next door to me about that.


Bill

 

[SEALman799]

Lol, come on now. We are talking about 20 bucks here. You spend 400 on a knife, but 20 for a harder blade is too much? In my experience 1-2 points can make a huge difference.

Plus the hardness is checked before and after re-hardening so you aren't going in "not knowing". I'd always tell paul if it's 59.5 before, then just send it back. Don't mind paying 20 to find out. Worth it for a knife I'm going to carry for years and years.

Damn, for 20 bucks I'm more than happy to send it out to just be tested.

 

[Lo/Rez]

I get all my sebenzas rehardened to 60 by Paul Bos Heat Treat, big difference. I find that is a perfect number for this steel personally.
Stock HT is just way too soft for me. I don't have any chipping issues at the higher hardness and no more edge flattening.

People always claimed nothing was wrong at 58-59, but CRK mid 2013 bumped it up to 59-60. They certainly don't make a change
for no reason. Going to have to pick up a post change CRK and compare to my hardened blades.

This is interesting. Is the thumb stud removed prior to heat treat? If so, does Paul Bos provide the service? If not, what does the thumb stud look like after? I'm assuming the blue changes color.