how to deal with metal surface maintenance

To let the plating effective are good and last long. we have to deal with the metal before plating. there  a lot stains there , Like the oil stains, wax stains, and oxidation or rust spot etc. All this will dierctory affect the plating is good or not.

Hence. for the metal processing factory. The first thing is to do degreaser for the processing metal.Why degreaser is so important. if the the metal surface have oil stains. this parts will not plating strong. and while other part is plating good. this parts there still not.