Spyderco Forums

It sounds like a good study for Todd Simpson to do (Science of Sharp).

It is a good one!

I had an initial article that predicte performance of SPY27. I then had a follow up with heat treating, toughness, and corrosion resistance. Then a third article had tested edge retention reported. The toughness was slightly worse than I predicted it would be and the edge retention was slightly bett...

Maxamet is a higher carbon, higher cobalt, slightly higher vanadium version of T15. CPM-T15 is normally tops out at 66, maybe 67 Rc. I would anticipate something like 64-66 Rc depending on how they want to heat treat it.

Thanks Sal I sent Gail an email

I’m working on a book on knife steel history right now and I can’t find a copy of The Spyderco Story for a reasonable price anywhere. I’m looking for someone who is willing to loan me a copy.

High entropy alloys are a hot topic for metallurgists and materials scientists right now, mostly at the University research level. They are not similar to "liquid metal" as those are non-crystalline while high entropy alloys have a crystal structure. I have not seen any high entropy alloys...

Thanks everyone it’s been a good birthday.

Thanks. No knives in my socks, unfortunately.

This is what I want to know. How do these differences in carbon and chromium make such a difference in the steels? Is 14C28N that much tougher and why? Is it the amount of chromium? Does that lead to bigger carbides and more brittleness in the BD1N? On the surface they seem similar, except that BD1...

The differences in carbon and chromium are quite significant between 14C28N and BD1N, and the microstructure and toughness measurements of the two steels demonstrate that. They are less similar than they appear to a layman.

Rex branding from Crucible started with high speed steel and has always been used as high speed steel branding ever since. https://trademarks.justia.com/700/41/rex-70041265.html

Even Crucible M4 is branded as Rex M4 or CPM Rex M4.

The article by Krauss also said they got their 440 stainless from Cyclops steel. In a book of available steel alloys it only lists 440A for Cyclops steel in the 1936 and 1945 editions, sold as “Stainless B” which is the generic term for 440A until the 440 designation was created.

Something I read. https://queencutleryhistory.com/index.php/historical-documents/#:~:text=view%20The%20Rise%20and%20Fall%20of-,Queen,-Cutlery Maybe the Ph.D has me fooled. Asking for a citation doesn’t mean I am questioning what you said, it means I need a citation. David Krauss, PhD, in his articl...

Wow. Awesome. Sal, many thanks for the story. Larrin, I realize this question will force you to work within extreme generalities, but, is there a relative humidity level over which you would expect modern high-carbide steels with low chromium %'s to corrode structurally over long periods of time (>...

I would like to see a citation for that. 440C didn’t exist until the late 30s and it wasn’t called 440c until years later. But for my steel history work I need citations. Edit: here is one of the claims - https://www.google.com/books/edition/Official_Price_Guide_to_Collector_Knives/Pa00KCEvIr0C?hl=e...

The first production knife super steels depends on whether or not you consider 440C or 154CM the first super steel. Gerber was using 440C in the late 1960s which was not long after it was being used in custom knives. It is quite possible that there were production knives using 440C before then but a...

Yes there can be several sources for stresses leading to warping which is why it is a long checklist for looking into why any individual knifemaker or heat treaters is seeing warping. It’s all pretty boring QA metallurgy stuff which probably sounds too alarmist for a forum like this that doesn’t hav...

electro-static wrote: ↑

Tue Jun 14, 2022 7:59 am

I think Larrin is also trying to tweak the formulation to eliminate warping as well, no?

No, the formulation is not changing. A few custom knifemakers said it warped more than they wanted and I said we will do our due diligence to look into it.

We have had reports of warping with long thin blades. Warping is relatively common with knives it is mostly about severity and frequency. The shape itself of a knife lends itself to a warp rather than other potential types of distortion that can occur during heat treating. As noted there are certain...