... :4.8 ,6.8,8.8..... Coupling Fasteners,Connecting Fasteners,Aluminum Fasteners. 1.What’s the specification of our Products ? MaterialCarbon ... good Aluminum.Meanwhile,we can use other materials accordingto customer's demand .ThreadType "M","UNC","UNF","BSW"thread are available ... procedure,products will be qualified when they reach in customer's hands .2.Recently,several New quality control equipments had ...