1. You will never need SS unless for shine somewhere. Pan head and oval head trims screws are SS.
2. On our old trucks, except for a few motor, driveline and suspension hardware, you can torque them as many times as you need to.
3. The only nuts you should not use twice are locking nuts. Nylon, deformed thread....
4. When dismantling a truck or motor, always save and reuse the hardware. Lock washers can be reused if not flattened. Rusty OK, Rusted no.
5. Grade 5 is all you will ever need.
6. McMaster Carr seems to have Gr 5 black oxide fasteners. Limited length bolt choices. Nuts no problem. Large quantities only?. EBay sellers buy these and break into small Qtys.
7. Could not navigate to black fasteners at MSC Industrial Supply.
