Flange bolts usually use Hex Bolt , Flange Nuts, generally hexagonal, and are divided into two types: single chamfer and double chamfer. analyse as below:

Bolts are divided into single-headed bolts and double-headed bolts according to their shapes. The single-headed bolts are only threaded at one end of the screw rod, and the other end is the screw head connected to the screw body. Single head bolts for flanges usually use hexagon head bolts. Both ends of the stud bolt are threaded and have a cylindrical shape. When the tensioning force is large, the single-headed bolt is easy to break at the connection between the screw rod and the screw head, so it cannot be used on medium and high pressure flanges. Stud bolts can not only be used on medium and high pressure flanges, but also easy to tighten from both sides

According to the manufacturing method, bolts are divided into rough bolts, semi-refined bolts and refined bolts. Except for the threaded part, the outer surface of the rough bolt is not finished, and it is the shape of the blank, which is relatively rough. The bolts are mostly made of ordinary carbon steel, and the tension force they bear is not high. Semi-refined and refined bolts need to be processed, and some are also heat-treated. They are mostly used in high-quality carbon steel or alloy steel, so they have large tension and high temperature resistance.

Flange Nuts, generally hexagonal, are divided into two types: single chamfer and double chamfer. The surface of the single chamfered hexagon nut and the connected part is flat, and only the other side is chamfered; the double chamfered hexagon nut is chamfered on both sides. Therefore, the contact area with the connector is that the single chamfered hexagon nut has a large contact surface, and the double chamfered hexagonal nut has a small contact surface.