What Are Fastening Components?
Fastening components are mechanical elements, such as bolts and nuts, that hold two or more objects together so that they do not shift position when they are combined. Fastening parts are not only tightened like screws, but also inserted like pins and keys.
Types of Fastening Components
There are various types of fastening components, but here are some typical examples.
1. Bolt
A bolt is a type of screw consisting of a threaded shaft and a head. There are hexagonal bolts with a hexagonal head and socket bolts with a hexagonal hole in a cylinder.
2. Nuts
Fastening components, mainly hexagonal columns with female threads, used in combination with bolts. Fine U nuts with an anti-looseness mechanism and washer nuts with washers are available.
3. Rivet
A rivet consists of a head and an unthreaded body. After the body is threaded into the hole, the body is crushed with a hammer to make it larger than the hole diameter, thereby semi-permanently fastening components.
4. Pin
Fastening components that are inserted into the hole. There are cylindrical parallel pins and conical tapered pins. Parallel pins are used as high-precision positioning pins.
5. Key
Fastening components that are inserted into a groove. Parallel keys, half-moon keys, sloping keys, etc. are available. They are mainly used in couplings and rotary shafts to prevent rotation.
6. Retaining Ring
Fastening components in the shape of a ring, mainly used to prevent loosening. There are retaining rings called E rings and C rings based on the appearance of their shapes. There is also a type of retaining ring called a snap ring that uses spring force.
Principle of Screw Fastening
When a bolt is used to fasten a material to be fastened, the bolt extends slightly and the material to be fastened contracts slightly. At this time, the bolt is subjected to a force in the direction of contraction to return to its original position, and the fastened member is subjected to a force in the direction of extension to return to its original position. These mutually repelling forces collide to hold the bolt and fastening components in place. The force generated at this point is called axial force.