AP 4057 is an ideal dry acid mixture for 200, 300, 304 and 400 series alloys which act as acidifier and scale remover for Stainless Steel and Titanium. AP 4057 is also pickling material for magnesium prior to chromating.

AP 4057 enables frosty etching of Silicon - Aluminium casting. For all these processes , surfaces should be free from oil and soil with suitable cleaning methods.