All kinds of stainless steel screws and customized fasteners can provide material range: SS201, SS304, SS316, SS410, etc. Welcome to call or email to inquire about detailed products. Hexagonal head bolt and screw head (cylinder) with external thread fasteners in two parts, with nut used for fastening the two parts with hole, their performance can be divided into 4.8, 6.8, 8.8, 10.9, 12.9, and so on, more than 10 levels, including a 8.8 and above the bolt is made up of low carbon alloy steel and medium carbon steel and heat treatment (quenching and tempering), known as the high strength bolts, the rest are called ordinary bolts.