... comb:M2-M8,#4-#10 4.Kinds of washer High Quality Combination Screw 1. Head type of Combination Screw ... :ASTM/JIS pan head,hex head,.high round head,cheess head,flat head...ect..2. ... . Surface of Combination Screw:Plain, black finished, Zinc plated (Galv), Nickel, phosphate black, 3Cr zinc,Passivation8. Packing of Combination ... DIA 7mm 7mm 8mm 12mm 15mm High Quality Combination Screw