Shot blast or sand blast CPM-3V

N

night man

Joined
Aug 27, 2010
Messages
199
I have 12 knives and 1 tomahawk that I will be sending to Peters for heat treating. All are CPM-3V. I am having them all HTed to 60HRC. I want to have them blasted afterwards. I will be painting some of them with KG gunkote and leaving the blasted finish on others.

My question is, should I have them shot blasted or sandblasted and what is the difference?

Thanks.
 
I don't feel that 60Rc is an optimal hardness for 3V. If you want maximum toughness, go for 58Rc. If you want the best edge-retention, go for 62Rc. There's no reason to "split the difference".

CPM-3V has a tendency to pit rather than patina. A coarse finish like bead-blasting will only make that worse.

For your blades that will not be coated, I strongly recommend a hand-satin or belt finish of at least 600-grit. The smoother the surface is, the less likely it is to rust or pit.

If glare is an issue, you can etch/passivate 3V with a soak in ordinary white vinegar; that will kill the shine and leave the blade with an attractive, even grey color.
 
so 58hrc on the tomahawk and 62 on the knives sound about right? I will only blast the ones that I will finish with KG gunkote. Thanks. I finish everything with A45 trizact and fine scotchbrite which brings the finish to around 500 grit belt finish.
 
You must log in or register to reply here.
Back
Top