1 1 4 coarse thread drywall screws

Galvanized wire coating rough, passivation film is not bright, bath temperature is too high. If the cathode current density is too high, zinc content in the bath is too high or sodium hydroxide and DPE content is too low; Electroplating solution with solid particles or excessive foreign metal impurities, will lead to such problems. Solution: If the large roll galvanized wire to the above coating is rough, there may be solid particles in the plating solution. If the roughness of the part is severe, the current density may be too high.

The physical methods mainly include manual rust removal and mechanical rust removal, chemical rust removal is generally the use of pickling method, practical application, usually according to the appearance of the workpiece rust status and different post-treatment process, choose different rust removal methods, among which pickling rust cleaning is more commonly used. That is, the iron and steel workpiece with oxide skin or rust is etched in the acid lotion, mainly to remove the oxide or rust layer on the surface of the steel.