... 3>dia:3.5,3.9,4.2,4.8mm countersunk phillips self drilling screws (factory)**key words: self tapping ... screws, drilling screws**Material: carbon steel C1022**head type: bugle head, Hexagonal head, countersunk head, wafer head, flange head, flat head, truss head, etc.**Feature: zinc coated (white, ... to other types of self dirlling screw as below: countersunk phillips self drilling screws (factory)