Standard combination of stainless steel screws refers to the national standard, which is often said that the country label, a cross-head, a cross hexagonal. That is, stainless steel pan head combination screws, stainless steel cross hexagonal combination screw, GB GB7474.8, GB9074.4. Stainless steel combination screw GB9074.8 refers to the stainless steel cross head small pan head combination screw. Stainless steel combination screw GB9074.4 refers to the stainless steel cross head combination screws, large pan head combination screw and small pan head combination screw is the difference between the pan head combination screw in the pan head screw head than small pan head combination screw in the disk Head screw head to a little larger, the thickness of the head should be thicker. Stainless steel cross hexagonal combination screw GB GB7474.13.