Copper As Carburizing Stop-off / Hydrogen Embrittlement

When carburizing a sems washer screw, what is the standard thickness of copper plating required on the washer to ensure protection of the washer during heat treat, and prevention of hydrogen embrittlement during the zinc plate/bake process. I cannot find a spec on this. Also, if the plater is not actually stripping the copper but applying a copper alternative on the washer, which is an additional plating process, could this enhance a hydrogen embrittlement issue?

Connie, have you considered machining a blank, then having it carburized and then machining the areas that you were going to "mask," then go back to heat treat and harden. This way those machined areas will be soft.

Rich.....