Carbide Tip Relief Angle?

[SWB]

What relief angles are you guys using on your custom tip profiles and for what materials/valve diameters?

I'm having a custom tip made and I'm not sure what relief to use. The 12 degree angle seems to dull a little faster than I'd like. I'm thinking that going to 10 or even 8 would help with longevity, but maybe not?

What do you guys think?

SWB

[LilRacr]

What are you cutting? I typically use less relief the harder the material. I like to use 4 to 6 degrees relief in general.