1. When someone buys a sheet of CPM 15V from the factory, does it arrive with an "off the shelf" heat treatment that is suitable for making a knife? Or does everyone purchase "raw material" that must be heat treated according to standard "recipes?"Deadboxhero wrote: ↑Sat Jan 14, 2023 2:20 amI'm excited that you guys are going to get more Spyderco CPM 15V. It was really fun getting you guys this Heat Treatment.
Great to know!Ramonade wrote: ↑Sat Jan 14, 2023 7:54 amI've been cutting a LOT with mine and a 9 micron gunny juice strop have been able to bring it back 99% each time. I'm only losing 1% at a time, very slowly, it's good !
Now that someone mentionned a Native 5 in this steel, I can't get it out of my head.... In G10 please!!!
I'd take a linerless G10 even the same brown. Would love to have that BBB logo on it. I can almost see it now.Ramonade wrote: ↑Sat Jan 14, 2023 7:54 amI've been cutting a LOT with mine and a 9 micron gunny juice strop have been able to bring it back 99% each time. I'm only losing 1% at a time, very slowly, it's good !
Now that someone mentionned a Native 5 in this steel, I can't get it out of my head.... In G10 please!!!
Totally ! I don't have a linerless N5 yet so it would make a good excuseBemo wrote: ↑Sat Jan 14, 2023 12:00 pmI'd take a linerless G10 even the same brown. Would love to have that BBB logo on it. I can almost see it now.Ramonade wrote: ↑Sat Jan 14, 2023 7:54 amI've been cutting a LOT with mine and a 9 micron gunny juice strop have been able to bring it back 99% each time. I'm only losing 1% at a time, very slowly, it's good !
Now that someone mentionned a Native 5 in this steel, I can't get it out of my head.... In G10 please!!!
. I try to combine 2 of these factors on each buy : new design, new steel, loved steel, good geometry, new construction, ...That would be a disaster if steel came in the hardened condition, there is a lot of processing done to convert a bar/sheet to a knife blank.
Of course, I used to work as a freehand professional sharpener and one thing that was noticed is some knives in the same steels but different manufacturers would sharpen differently.
Dude, that stuff is fascinating. Thanks for sharing the knowledge!Deadboxhero wrote: ↑Sat Jan 14, 2023 12:29 pmThat would be a disaster if steel came in the hardened condition, there is a lot of processing done to convert a bar/sheet to a knife blank.
The steel comes in the annealed condition
The steel manufacturer makes into a billet from raw materials.
The rolling mill processes the billet into different size sheets by hot rolling which also improves the structure, afterwards its annealed which further improves the structure and makes it ready to process and further HT into hardened condition when ready.
Of course, I used to work as a freehand professional sharpener and one thing that was noticed is some knives in the same steels but different manufacturers would sharpen differently.
Isn't that odd?
I remember being smitten at the time by the wonderful sharpening experience of Aogami Super, the shop I worked at specialized in Japanese cutlery and water stones.
Tojiro is a mass production japanese kitchen knife company, at the time they had a special run with san mai aogami super for a low cost.
Meanwhile Bladesmith Fujiwara Teruyasu also had knives in Aogami Super and the difference was breath taking.
Isn't that fascinating?
The NAME of a steel on the side of the blade is not universal
While the properties are pretty fixed to the chemistry there is certainly a range of expression, not to say 420HC and be heat treated to Rex 121 or vice versa.
Can't turn lead into gold.
On the Fujiwara, edge came up so crisp and deburred with great elegance (at the the time from what I had experienced prior.)The Tojiro was more stubborn on the burr and also did not hold the front end sharpness as well.
My mind raced
"How is this possible?" "What is going on?" "How does this work?" "I must KNOW!"
My curiosity of what makes the same steel sharpen better and hold the front end sharpness better became an all consuming obsession, an "idée fixe"
That was many years ago and was certainly one of many moments that set me on a curious quest to get answers to my questions.
Well almost 10 years later I have a pretty solid working understanding of how to create what I'm looking for that isn't simply a matter of HRC, it really comes down to the microstructure making up that given HRC.
Some features that make up the microstructure are more desirable than others, because the apex is so small and cannot be seen by the naked eye microstructure is important.
Deadboxhero wrote: ↑Sat Jan 14, 2023 2:20 am
Color Metallography of CPM 15V
I made this micrograph
this is what the structure of the Spyderco 15V looks like at a microscopic level. The circular "blobs" are significantly harder than the surrounding matrix, they are also responsible for increasing the slicing edge retention.
These "blobs" are called carbides, these ones in particular are all vanadium carbides which are the hardest commonly available in knife steel.
The largest ones range from 3 to 4 microns, that's under half the size of a human red blood cell.
These carbides make up 23% of the steel matrix.
Compared to 17% in 10V and 8% in 4V. This increases resistance resistance to wear at the edge and can increase strength.
I'm excited that you guys are going to get more Spyderco CPM 15V. It was really fun getting you guys this Heat Treatment.
Not on this one, we can definitely geek out and use different etchants and etching protocols to highlight certain and specific features in the future when I'm less busy changing diapers : pBuddafucco wrote: ↑Sat Jan 14, 2023 6:47 pm
Is there any significance to the different colors in your micrograph? Or am I over thinking it?
On the surface, it DOES seem odd--until you start to think about it. I clarify things in my mind by making analogies. Heat treating is like baking a loaf of bread. You can give flour, water, and yeast to two different chefs, and the result will be two vastly different loaves of bread. And of those two loaves, there is no right or wrong. Each one can be better suited for a specific purpose. How dull would life be if there was only one kind of bread... or one type of knife steel?Deadboxhero wrote: ↑Sat Jan 14, 2023 12:29 pmsome knives in the same steels but different manufacturers would sharpen differently.
Isn't that odd?
Mushroom wrote: ↑Sun Jan 08, 2023 9:41 pmI haven’t been following this thread too closely but it seems like as good of a time as any to promote the “Random: General Spydie Chat” thread.” It was made specifically for off topic chatter.
“Random: General Spydie Chat” thread
LOL! You’re right!awa54 wrote: ↑Sun Jan 15, 2023 12:34 amMushroom wrote: ↑Sun Jan 08, 2023 9:41 pmI haven’t been following this thread too closely but it seems like as good of a time as any to promote the “Random: General Spydie Chat” thread.” It was made specifically for off topic chatter.
“Random: General Spydie Chat” thread
Dang! and here I was thinking that this was the place for OT convos: viewforum.php?f=5
...
Thanks, man. I hadn't seen that one yet.Ricey_9 wrote: ↑Sat Jan 28, 2023 1:43 pmhttps://youtu.be/h6DwlT2NDtU
Haven’t seen this posted anywhere figure i would share.
I would love to see a manix LW in 15VTTFulltimer wrote: ↑Wed Feb 01, 2023 7:03 pmEven if Spyderco rivets it, you can make it a screw model in about 15 minutes.
