Crank

I'll be brutally honest, never heard of re-hardening the crank after cutting; what is the process they propose to use to re-harden the crank? I can see the possibility of the crank becoming brittle after such a process.

When any of the factory crank were hardened at the factory, they were only surfaced hardened, only to a depth of .002 to .003 of an inch; other wise they were of a uniform hardness thru out.