1.Bolted connection
a)Ordinary bolt connection (tension bolt connection) - the connected part is not too thick, the screw has a nail head, the through hole does not have thread, and the screw passes through the through hole to cooperate with the nut. After assembly, there is a gap between the hole and the rod, which shall not disappear during work. It has the advantages of simple structure, convenient assembly and disassembly, multiple assembly and disassembly, and is widely used.