Nitriding and crank grinding

Cryogenics ? Like what ? dipping it in Liquid Nitrogen. I don't see how this will harden the material, and for that matter, this is a "cast" crank we are talking about here, not a forged crank.

Cast steel is stable and will NOT distort anywhere near what a forged steel crank would, when put under these conditions (or heat treat).

This is why forged cranks should be stress relieved after machining/prior grinding.

Either way (forged or cast) Nitiding it will not hurt.

I do have to agree with the removing a large part of the rads, you will for sure loose way to much strength, and the cast cranks are already weak.

Nitride is surface hardening only, will only help slow down wear factor.

I strongly feel that machining your crank in this manner, however inexpensive it may be...it's a timebomb ticking.

Don't do it.

My ramble.