Bolts can be divided into A, B and C grades according to the production accuracy.
Class A and B are refined bolts, and class C are crude bolts.
For connecting bolts used in steel structures, unless otherwise specified, they are generally C bolts of common rough manufacture. There are differences in the methods of different grades of processing.
At the same time, the general building structure of the main component of the bolt connection, generally adopt high-strength bolt connection.
High strength external hexagon bolts
Galvanized/ natural color/boiled black