STUD BOLTS Standard 304 Stainless Steel Fasteners, 18-8-Stainless Steel, A270, A280, ASTM F2281, F738, F837, F593A/B/C/D, F594A/B/C/D, Hex Bolt, Nut, Stud, Screw, Washer Metric Size Range from M1.0 upto M150 in accordance with ANSI / ASME B1.13M Edition 2012. Imperial size Range from #0000 upto #12 and 1/4" upto 6" in accordance with ANSI / ASME B1.1 Edition 2012. Threading Specification Coarse Threads (6g / 6H Tolerance), Fine Threads (4g / 4H Tolerance) and Extra Fine Threads in Metric Series in accordance with ISO 724. Unified Coarse, Unified Fine, 8 UN Threads in accordance with ANSI / ASME B1.1 2A / 2B Edition 2012.