What is the Bolt?

Bolt: by the head and rod (with external threads of the cylinder) composed

of two parts of a class of fasteners, need to cooperate with the nut, used to

fasten the connection of two components with through-hole. This form of

connection is called bolt connection. If the nut from the bolt screw down,

can make the two parts separate, so the bolt connection is a removable 

connection.