Steel structure has been applied in many engineering construction fields nowadays, so its design, construction, use and maintenance involve all aspects and are interrelated systems engineering. When it comes to steel structure, it can not be separated from the connection form of steel structure, especially the connection of fasteners, including ordinary bolts, high strength bolts and shooting nails. Fixed connection of self-tapping nail and rivet.
Connecting bolts are classified into 8 grades, namely 3.6, 4.6, 4.8, 5.6, 5.8, 6.8, 8.8 and 10.9S (for example, 5.6S means tensile strength of 500 MPa and yield-strength ratio of 60%). The latter two grades are high strength bolts, and the others are ordinary bolts.
Ordinary bolted connection
(1) Types and uses of common bolts
The common bolts are hexagonal bolts, double-headed bolts and anchor bolts according to their shapes.
Hexagonal bolts: According to quality and product grade, they are divided into three types: A, B and C.
Class A bolt - refined bolt;
Class B bolt - semi-refined bolt;
Class C bolts - rough bolts.
Class A and B bolts are suitable for the installation of important structures which need to transmit large shear force at the connecting parts, and Class C bolts are suitable for temporary fixing in the installation of steel structures.