What Is a Coupling Nut?
A Coupling Nut is a nut that connects two bolts together to increase the height of the bolt.
Coupling nut shapes are mostly hexagonal, as are most nuts. However, because of their long length, the product as a whole has a hexagonal prism shape.
Coupling nuts are provided with a set screw or male thread on both end faces. There are various types, such as those with a female thread on one side and a male thread on the other side, those with female threads on both sides, and those with male threads on both sides.
Coupling nus are also known as high nuts, long nuts, joint nuts, connecting nuts, hexagonal posts, etc.
They are also sometimes called spacers because they create space. Note, however, that a spacer can also refer to a simple cylindrical pipe with no male or female threads.
Uses of Coupling Nuts
An example of where coupling nuts are often used is around motherboard connectors in computers. Coupling Nuts make it possible to create spaces that do not collide with neighboring cases or boards, or to stack multiple boards on top of each other.
It is also possible to create a simple case by sandwiching the boards between the posts. Screws on the connector side can be tightened to secure the connector. Aside from electronic devices such as computers, coupling nuts are also used to secure tools that are installed in construction or outdoors.
Specific examples of use include connecting flexible threaded rods in sports facilities, trampolines installed as playground equipment, and campgrounds.
In towns, coupling nuts are responsible for adjusting the height of vending machines to make them level when they are installed.
Principle of Coupling Nut
A coupling nut has a female or male thread on both end faces and a total length that allows it to connect two threaded parts in its role, keeping the distance between them.
The helical slope of the screw has an angle, called the lead angle, which allows the position to be adjusted arbitrarily by turning the screw. The screw is generally a right-hand thread, which means that when turned clockwise, the screw advances toward the back.
This advancement of the screw makes it possible to adjust and secure even the most delicate positions. The distance between the two end faces also allows for spacing between the two parts.
Other Information on Coupling Nut
1. How to Prevent Loosening of Screws With Double Nuts
The double nut method is a method to prevent the screw from rotating and loosening due to vibration or other reasons, resulting in misalignment of the screw, not limited to coupling nuts. This method prevents rotation and loosening of the screw by tightening two nuts facing each other.
The double nut method can also be used to prevent loosening in positioning by using a double nut.
2. Material of Coupling Nut
Most coupling nuts are made of steel materials, such as S45C, SWCH (carbon steel wire for cold heading), SS400, and other alloy steels, and stainless alloy steels such as SS304 and XM7. As with general screw parts and hexagon nuts, surface treatment includes trivalent chromate plating, and even plating with black-dye treatment.
If stainless steel is selected, corrosion resistance will be higher, but it should be noted that the cost will be higher. It is recommended to select the most suitable material depending on the environment and purpose for which the coupling nut is used.