What Is a Clinching Fastener?
A clinching fastener, also called a self-clinching fastener, is a type of screw.
A clinching fastener is a nut-like fastener that is press-fitted into a drilled hole in a plate or other material to make it easier to attach a screw or other fastener.
A clinching fastener can be used with various types of fasteners, such as spacers and studs, to provide stable fastening force and a beautiful finish.
A clinching fastener is increasingly used in sheet metal products because of its space saving, lightweight, and reduced number of parts, which is in line with the recent miniaturization of home appliances.
Applications of Clinching Fasteners
A clinching fastener is used in a wide range of applications, including thin sheets that are difficult to screw together and places where welding is not possible.
For example, a flat-panel television set, if it is a rather large one, has about 200 clinching fasteners of various lengths.
In other words, a clinching fastener is an important design item in miniaturizing consumer electronics.
Other major products include personal computers, communication devices, automobiles, transportation equipment, aerospace, machine tools, and industrial robots.
Other applications include medical equipment, construction, measuring instruments, amusement, and many other fields.
Principle of Clinching Fasteners
A clinching fastener is a press-formed fastener that provides a high-strength fastening force. The fastener is placed in a hole drilled in a base material, such as a plate, and the shank and pilot portion of the fastener are forced into the base material through plastic deformation.
Clinching fasteners are available in various types and can be selected to meet your needs.
Clinching nuts are used for fastening electronic components on boards.
A bolt is used to tighten the clinching nut from the underside.
A clinching fastener was the first of its kind in the world.
The process of attaching a female thread to a plate has been a routine part of sheet metal work for many years, and the method used was to burr the plate and then cut the thread.
The problem here is that when using 1mm-thick sheets, which are often used in sheet metal processing, only about three threads can be cut (or made), and as a result, the part to be fixed cannot be firmly secured.
However, it should be noted that the shape of the clinching portion of the clinching nut, called the skirt, has a slightly lower fastening force than that of spacers, and that the plate may warp, especially when multiple nuts are press-fitted into a single product. Tools should be used to solve these problems.
A clinching fastener, a spacer, is the conventional method of inserting the pilot of the clinching fastener into the drilled base metal and press-fitting the knurled part.
Studs are a method that can provide high fastening force.
The surface of the base metal on the flange side is finished flat, and post-treatment such as polishing is not required.
Spacers are press-fitted into a hole in the base metal, allowing them to stand up vertically while providing a very flat surface.
When press-fitting clinching fasteners, it is essential to use not only a simple press but also a jig depending on the product.
The selection of a simple press machine is performed by referring to the press-in force listed in the performance table of the product to be used, and using a press machine that can apply pressure at or above that press in force.
If the pressure is too weak, it may cause the product to fall off.
On the other hand, if the press-in force is stronger than necessary, not only will the sheet metal be scratched or deflected, but it will also deform the product, causing it to drop out or become screwed in, so care must be taken here as well.