... standard. 2. material: steel, 3. finish: zinc non-standard flat head socket rivets with internal thread1.Standards:DIN ,ANSI/ASME,BS,GB ... Korea,Southeast Asia ,etc.Professional production and processing: nut, nuts, pin shaft, stud bolt,screws, bolts, non-standard bolt, non- ... , 10.9 and ANSI Grade 2, 5 and 8.7. Various nuts, flat gaskets, spring washers, mechanical bolts, tapping screws, fibreboard ...