Okay, sorry for the delay
been a bit busy in the shop. Thanks for all of the comments!
Time to heat treat the blade. We do all of our own heat treating. When we first started making knives in 2012, everything went to Peters Heat Treating, and that was great.. but Im guessing a lot of knife makers feel the same way, and you want to eventually have full control over each step of the process. Anyway, in this pic I am going to heat treat the folder blade with some Urge knives - all CPM S35VN
Air hardened steel, so they each get wrapped in foil.
Ready to go in the oven.
We use Evenheat ovens with the Rampmaster controller. After I have wrapped the knives, the oven gets turned on and begins the program. I typically put the knives in the oven around 400-500 degrees.. the oven then makes its way up to 1575 degrees and held there for 10 minutes. After 10 minutes, the oven then ramps up to 1950 degrees. After at least 20 minutes the knives are removed from the oven
and right between two 1 thick plates of aluminum. I place a heavy weight on the top aluminum plate to hold pressure on the knife blade.. I prefer air hardened steels over oil quenched as it seems to have a better chance to prevent warping. The knife blade stays in the plates for 2 minutes.
After the knife is removed from the plates, it goes into a 3 liter dewar of liquid nitrogen for 4 hours. We use wire to suspend the knives in the liquid nitrogen. After the knives are removed from the liquid nitrogen, they are set out and warmed up to room temperature. Then they go into a tempering oven (not shown) for 2 x 2hour each tempers at 400 degrees.
They are then check with our hardness checker.. and that will almost always get us right at 60HRC.
Alright, so after all of that, its time to move forward with the finish of the blade. I know I want to blast/stonewash the bevels of the blade, so its back in the sand blast cabinet.
I rolled up some masking tape and stuffed it inside the pivot hole to protect it from the grit. Again, using 220 grit media.
After blasting.
Another pic.
After blasting the knife, I spray a little WD-40 on it and into the tumbler for 45 minutes.
The tumbler is crazy loud, so it is out in the barn away from inside the shop.
Model of the tumbler.. my father found this on Craigslist, I believe.
Blade post blasting and tumbling in ceramic media.
More to come.. Ill speed it up.
Thanks again
Shannon