Drywall Screw 1)Finishing:Phosphating,ZincPlated 2)D:2.9-6.3mm ... 3)Certificate:ISO9001:2008 4)Package:Cartons,P Drywall Screw:Specification:DIN,JIS,ASME and according to customers' requirements.Surface treatment: Phosphating( ... machinery,construction,transportation,electricpower,electronics,chenicals,home appliances,military inductry and other industries.custom-made basisWaiting for your reply,hoping ...