Mechanical properties of fasteners Bolts, screws, studs and nuts GB 3098.6 Mechanical Properties of fasteners Stainless steel bolts, screws, studs and nuts GB 3103.1 Fastener tolerances Bolts, screws and nuts GB 5267 Electroplating of threaded fasteners GB 5779.1 Surface defects of fasteners — Bolts, screws and studs — General requirements GB 5779.3 Surface defects of fasteners — Bolts, screws and studs — Particular requirements.

High strength double head bolt, material: 35#, 45#, 35CrMoA, 25Cr2MoV, 304, 316, 304L,

316L, 2H, 2HM, B7, B7M, B16, B8, 8, B8M, 8M, widely used in power, chemical, oil refining, valves, railways, Bridges, steel structure, auto parts and other fields.

Double bolt function: generally used in mining machinery, Bridges, cars, motorcycles, boiler steel structure, crane tower, large span steel structure and large buildings.

The expression method of double-headed bolt: general double-headed bolt is expressed as :M12×100 GB 901-88(standard) 35#/35#(material)8.8 /8 (modulation level) meaning: diameter =12mm length =100mm GB 901-88 The use of national standards (of course, you can also use industry standards according to need)