1,Purpose: steel structure fastening, etc 2,Quality assurance preferential price 3,Prompt delivery, and transportation safet 1, ... ISO 15480, ISO 15481, ISO 15482, ISO 15483,Countersunk Head Self drilling and Tapping Roofing Screws;DIN7504K,SAE J78,ISO 15480, ISO ... ,Nylon Head Self Drilling and Tapping Roofing Screws;DIN7504K,SAE J78,ISO 15480, ISO 15481, ISO 15482, ISO 15483,Concrete Screw;DIN7504K,SAE ...