A type of fastener consisting of a head and a screw (a cylinder with an external thread), which needs to be matched with a nut to fasten and connect two parts with through holes. This form of connection is called a bolted connection.
If the nut is unscrewed from the bolt, the two parts can be separated, so the bolt connection is a detachable connection. Bolts are also a type of railway accessories. Railway accessories are an integral part of railway lines. The tracks referred to here include steel rails, sleepers, connecting parts, ballast beds, anti-climbing equipment, rail braces and turnouts.
As an integral engineering structure, the track is laid on the roadbed, which plays a guiding role in the operation of the train, and directly bears the huge pressure of the rolling stock and its load.
Under the power of the train's operation, its various components must have sufficient strength and stability to ensure the safe, stable and uninterrupted operation of the train according to the specified maximum speed.
According to the way of receiving the connecting force: divided into ordinary and with hinged holes. Ordinary main bearing axial force, can also bear less demanding lateral force. The bolts used for the reaming hole should be matched with the size of the hole and used when subjected to lateral force. According to the shape of the head: there are hexagonal head, round head, square head, countersunk head and so on. Among them, the hexagonal head is the most commonly used. Generally, the countersunk head is used where the surface is required to be smooth without protrusions, because the countersunk head can be screwed into the part.
Round heads can also be screwed into parts. The tightening force of the square head can be larger, but the size is large. In addition, in order to meet the needs of locking after installation, there are holes in the head and holes in the rod. These holes can prevent the bolts from loosening when they are vibrated.
