First, Dacromet coating thickness ranges from 5 to 40 microns with uneven coverage. It will accumulate on tiny threads, alter thread medium diameter and block thread root, resulting in failed tapping and assembly mismatch.

Second, Dacromet requires curing at 300℃, which blunts the drill point. The coating peels off easily during drilling and ruins the self-drilling function.

In addition, carbon steel & 410 stainless steel substrates have mismatched thermal expansion coefficients with Dacromet, causing coating microcracks and peeling after production.