Building a Custom Knife for Sal: CPM S60V

[ChrisinHove]

Fantastic thread. Craftsmanship, science and innovation in one. Add to that the redemption of an old villain (s60v, not Sal) and it’s a real treat.

[Wartstein]

Fascinating and insightful thread!

Agreed, thanks for sharing @Deadboxhero

[weeping minora]

Smells like another (re)addition to the Spydie Steel line-up is cooking !

[JoviAl]

This is really fun to read, thanks for sharing

[legOFwhat?]

Exciting thread!

[p_atrick]

Shawn,

Was the micrograph for S60V done on Sal’s knife, i.e. was it dome pre-heat treat? If so, I thought the heat treating process changed the microstructure. I’ve heard expression like “grain size” and “grain growth” with regards to heat treat.

[Ramonade]

I know the price of most PM steels in Europe and they're not cheap, especially CPM in low quantity (Bohler is closer so that's normal). I still felt like the cost was high for one knife but then I saw the size of the knife, understandable.

[electro-static]

It’s wonderful see this, I’m curious how the blade will turn out and perform.

[Guts]

Thanks for sharing this BBB. S60V sounded like a great steel on paper and I wondered why it wasn't really in use today not having any personal experience with it. That's interesting it has a finer microstructure than S90V and M390. Makes me want to try sharpening some. Can't wait to see the final product.

[Deadboxhero]

When you heat treat this blade, are you using a "recipe" that is published by others?

No

Do you use your own recipe arrived at through your own experimentation?

My own

Or are you able to look at the specs, and intuitively know what you need to do?

Institution doesn't work, without measurement there can be no improvements.

[Deadboxhero]

Shawn,

Thanks for sharing, always good to see how your knives are made.

What are you going to use for a handle? I have a lot more luck working with wood and have a ton of fun making handles for my mules. I have some Gabon Ebony I want to try next but running out of excuses to buy more mules.

Can’t wait to see the final product.

I prefer synthetic materials, PM me your address and I'll send you some for your next mule.

[Deadboxhero]

Fascinating stuff, Shawn. Thanks for the micrographs, those are really interesting to see! You pull no punches when it comes to big kitchen knives with the high carbide steels. That big 15V kitchen knife you made some time back still haunts my thoughts from time to time (in the best way).

Thank you, that was a beautiful piece.

[Deadboxhero]

Good thread!

I knew that you were heavily involved in knife making, but had no idea you had all of that equipment.

Do you take orders for knives at this time?

I've been brought to a crawling pace with raising two beautiful children. They are currently 1 and 3 years old so things will pick up when they get older.

[Deadboxhero]

Shawn,

Was the micrograph for S60V done on Sal’s knife, i.e. was it dome pre-heat treat? If so, I thought the heat treating process changed the microstructure. I’ve heard expression like “grain size” and “grain growth” with regards to heat treat.

I certainly could do metallography on the knife but it will look the same as the specimens that I cut and mounted.



Mounting makes it easier to polish and I'm sure you can imagine the laborious nature of getting a mirror polish on something especially if it's a very large area not to mention the expensive consumables involved.


Yes, terms like grain size and grain growth are common terms in metallurgy.

[Deadboxhero]

I know the price of most PM steels in Europe and they're not cheap, especially CPM in low quantity (Bohler is closer so that's normal). I still felt like the cost was high for one knife but then I saw the size of the knife, understandable.

Yes, it's funny because a lot of us start making knives because we don't wanna spend the big money on the coolest stuff.

Well.


It's a big lie.

it's cheaper to buy em

[Bolster]

CPM S60V


CPM S90V


Bohler M390



The color metallography colors the different carbide types differently, CPM S60V has a higher volume of vanadium carbides than M390...

I've not seen color metallography before! Can you tell us what colors represent the various carbides? I see tan, dark red/brown, white(ish). I notice the matrix color also changes.

Thanks for the thread.

[sal]

I know the price of most PM steels in Europe and they're not cheap, especially CPM in low quantity (Bohler is closer so that's normal). I still felt like the cost was high for one knife but then I saw the size of the knife, understandable.

Yes, it's funny because a lot of us start making knives because we don't wanna spend the big money on the coolest stuff.

Well.


It's a big lie.

it's cheaper to buy em

To be fair, When companies like Spyderco purchase steels in larger quantities, we pay less for the steel, than individuals purchasing from dealers in single pieces.

sal

[Ramonade]

I know the price of most PM steels in Europe and they're not cheap, especially CPM in low quantity (Bohler is closer so that's normal). I still felt like the cost was high for one knife but then I saw the size of the knife, understandable.

Yes, it's funny because a lot of us start making knives because we don't wanna spend the big money on the coolest stuff.

Well.


It's a big lie.

it's cheaper to buy em

God yes, I am thousand of euros in already and I have yet to make something else than XC75 (I think the US name is 1074 or 1075) and 14C28N fixed blades. I can't even heat treat by my own means yet. Well I could, but I don't believe in hail mary quenches !

Of course I could do all of that for way less, but when you want to do good things, you have to do it right and don't burn steps (it's what I believe, not an absolute truth, I prefer to clarify now before someone comes and argue, it's the internet after all ).

[Deadboxhero]

CPM S60V


CPM S90V


Bohler M390



The color metallography colors the different carbide types differently, CPM S60V has a higher volume of vanadium carbides than M390...

I've not seen color metallography before! Can you tell us what colors represent the various carbides? I see tan, dark red/brown, white(ish). I notice the matrix color also changes.

Thanks for the thread.

The white colored spheroids are "chromium carbides."
The reddish, orange gold shaded ones (depending on the micrograph) are the "vanadium carbides."

The background is the the matrix.

If you look closely at the S90V you can see the another level of complexity in how the MC (vanadium carbide) is forming out of the M7C3 (chromium carbide) or vice versa due to the partitioning of metallic elements when the steel was cooling and or heating from dissolution and or recrystallization temperatures.

Really shows when we say "Chromium" carbide we are simplifying it from (Cr,V,Mo,Fe)7C3 or "M7C3"

[Doc Dan]

Fascinating thread! Thanks, Shawn.