... surface:zinc plated , black , plain , H.G.D grade:4.8 , 8,8 Our main products are bolts, screws, nuts, machine screws, plain ... galvanization, and Dacromet. Our products are produced in conformity with DIN, ANSI, AS, BS, JIS, GB and ISO standards, non-standard ... specifications or upon our customers' special requirements, in grades 4.8, 6.8, 8.8, 10.9, 12.9, A2-50, A2-70, and ...