Basically, I was reasonably sure that the Spyderco's K294 was hardened to 63.5 HRC, but I was questioning what Kizer likely hardened to. Being that it's sort of a budget brand, it seemed reasonable to assume they probably did not run it as hard as Spyderco would. I also had BESS data to support that both knives were performing neck-and-neck (with differing edge angles), and so I used Larrin's regression formula to see what hardness Kizer's 10V steel would be at in order for the TCC figures to be neck-and-neck, and with both respective edge angles of 27 inclusive and 32 inclusive. With that 5 degree diference between the two, I had to adjust the suspected hardness of the Kizer to 58.5 HRC before the TCC figures matched with the same closeness as my own BESS data.
I have wondered for a while just how reliable that estimate could be, but since then have seen several reports of people with 10V Sheepdogs reporting HRC figures that support it being an accurate estimate.
I have had people offer to run it on their hardness testers for me and been meaning to follow up on the offer just to see how close the estimate actually was, but I don't have much reason to doubt it. Eventually I'm going to just buy some hardness testing files and I will bet money that it falls into the 58-60 range.
Anyway, point being, in that specific case it can be useful to confirm suspicions with less access to equipment? I mean, sure, I had a laser goniometer and a BESS tester so I can't exactly say without access to "special" equipment, but a Rockwell tester is sure a lot more expensive than either of those, but I was still able to draw a reasonable assumption that Kizer ran their 10V softer and then actually calculate a figure that was later confirmed using the formula.
For folks reading that don't understand the difference edge geometry can make and the usefulness of the regression formula.
The CATRA regression formula Dr Larrin made is useful for sandboxing differences and was built on over two decades of CATRA data.
We can take too drastically different steels and compare them with different edge geometry.
15° per side.
20° per side.
There's a big difference between 15dps and 20dps
What's crazy is we can out cut Maxamet at 70rc with 52100 using extreme geometry.
52100 at 10dps vs Maxamet at 20dps
Now of course in the real world we don't have a fixed load of cutting force and most people don't accurately create exact angles.
However the regression is very useful for exploring things and ruling things out.
How about 15V at 10dps?
What would you like it compared to? What hardness?
S30V I suppose, with the standard spyderco HT. Curious how much of an edge retention gain I'll see in 15V over S30V in the same model.
Re: VG10 Wear Resistance
Posted: Wed Feb 05, 2025 6:13 pm
by Deadboxhero
Here is the classic
"I don't see much difference between steel A and steel B"
with no accounting for edge geometry.
Here is the reality that nothing is actually perfectly flat to the apex. We find there is some convexing at the apex that can kill some edge retention if it's not measured or observed.
"I don't see much difference between steel A and steel B"
with no accounting for edge geometry.
Here is the reality that nothing is actually perfectly flat to the apex. We find there is some convexing at the apex that can kill some edge retention if it's not measured or observed.
I might press a 15V Para 3 into box cutting duties. For my 15V Military 2 and Yojumbo, I would be using them for self defense.
"I don't see much difference between steel A and steel B"
with no accounting for edge geometry.
Here is the reality that nothing is actually perfectly flat to the apex. We find there is some convexing at the apex that can kill some edge retention if it's not measured or observed.
I might press a 15V Para 3 into box cutting duties. For my 15V Military 2 and Yojumbo, I would be using them for self defense.
"I don't see much difference between steel A and steel B"
with no accounting for edge geometry.
Here is the reality that nothing is actually perfectly flat to the apex. We find there is some convexing at the apex that can kill some edge retention if it's not measured or observed.
I might press a 15V Para 3 into box cutting duties. For my 15V Military 2 and Yojumbo, I would be using them for self defense.
At what dps should I be sharpening these?
What's the best length for a piece of string?
I'll test out my new Spyderco sharpening systems. I'll test them until I get a roll or chip.
"I don't see much difference between steel A and steel B"
with no accounting for edge geometry.
Here is the reality that nothing is actually perfectly flat to the apex. We find there is some convexing at the apex that can kill some edge retention if it's not measured or observed.
I might press a 15V Para 3 into box cutting duties. For my 15V Military 2 and Yojumbo, I would be using them for self defense.
At what dps should I be sharpening these?
What's the best length for a piece of string?
I'll test out my new Spyderco sharpening systems. I'll test them until I get a roll or chip.
That's the spirit, the steel is capable of very low edge angles but the greatest variable of all is the end user, how they use it and for what.
No one size fits all.
Re: VG10 Wear Resistance
Posted: Thu Feb 13, 2025 12:03 am
by Bill1170
At age 10 my father taught me to sharpen my carbon steel pen knife, freehand. The angle was closer to 10 dps than 15 dps. I still retain that muscle memory over 50 years later. My edges lasted well and cut very well. As was stated above, a lot depends on the user; I was a careful boy. Being responsible for maintaining my own edges instilled respect for the edge.
