Supply all kinds of hex socket head bolts, hex bolts, square head bolts, carriage bolts, studs, anchor bolts, U-bolt, T bolt, track bolts, flange bolts, guardrail bolts, steel bolts and a variety of difficult heterosexual non-standard, various specifications of standard and non-standard nuts, washers and studs. Grade range: Grade 4.8 to Grade 12. 9. Materials:steel and stainless steel. Surface treatment: zinc plated, black, hot dip galvanizing, plain and so on. We can also produce products according to customer's samples and drawings.