Hexagon bolts are a kind of fasteners composed of a head and a screw. According to their material differences, they can be mainly divided into iron bolts and stainless steel bolts. The iron is graded by 4.8 bolts and 8.8 bolts. Stainless steel bolts are made of stainless steel SUS201 bolts, SUS304 bolts, and SUS316 bolts.
As a commonly used fastener, in practical applications, hex bolts usually need to be used with a nut, that is, for fastening two parts with through holes. This type of connection is called a bolted connection. If the nut is unscrewed from the bolt, it is possible to separate the two parts, so the bolt connection is a detachable connection. The bolts for steel structure connection are classified into more than 10 grades of 3.6, 4.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9, 12.9, etc. Among them, the bolts of grade 8.8 and above are made of low carbon alloy steel or medium carbon steel and heat treated. (Quenching, tempering), commonly known as high-strength bolts.
Others are ordinary bolts. For the time being, the performance grade label for hexagon bolts consists of two parts, which represent the nominal tensile strength and yield ratio of the bolt material.