AISI 1040 equivalent to EN8/080M40. An unalloyed medium carbon steel. AISI 1040 is a medium strength steel with good tensile strength. Suitable for shafts, stressed pins, studs, keys etc. 1040 must be pre-heated to 300 to 500 degrees F before welding and reheated to between 1100 degrees F and 1200 degrees F after welding. AISI 1040 Fasteners:Bolts, Screws, Stud Bolts, Nuts, WashersAISI 1040 fasteners includes bolts, screws, stud bolts (studs), threaded rods, nuts, washers and custom fastening parts. These carbon steel fasteners are produced with complete metric and imperial size range with ISO, Unified UN, UNC, UNF, UNEF, BSW & BSF thread profiles. AISI 1040 boltings are produced by hot forming and machining to size.