... blast4.bottom case:silver-alloy brazing,tin soldering5.other sizes and types are workable7. Parts can be supplied according to customers' drawings ... Black,Color Coating,Dip Tin,etc.Major Equipment:Stamping machines,Punching machine,Cutting machine,Sintering machine,Seam welding machine,Spot welding machine, Milling machine,Turning machine,Grinding machine,etc.Certification:ROHS Compliant ...