Shaft collars can be welded with some exceptions. Mild steel and stainless steel materials contain sulfur and other additives which allow for welding. However, the lowest possible current and adequate ventilation should be employed. Be sure to remove screws before welding. However, in no cases should collars with zinc plating be welded. The welding process on a zinc plated product will produce noxious fumes. Welding can be done safely on a black oxide finished product. Extreme caution is recommended when welding imported collars because of the inconsistency of the material and finishes.