1,Purpose: steel structure fastening, etc 2,Quality assurance preferential ... , ISO 15483,Painted Head Self Drilling and Tapping Roofing Screws;DIN7504K,SAE J78,ISO 15480, ISO 15481, ... ISO 15483,Modified Truss Head Self Drilling and Tapping Roofing Screws;DIN7504K,SAE J78,ISO 15480, ISO 15481 ... , ISO 15483,Countersunk Head Self drilling and Tapping Roofing Screws;DIN7504K,SAE J78,ISO 15480, ISO 15481, ...