Fastener Installation | FAQ | Glossary of Terms | Anatomy of Self-Clinching Fasteners | Self-Clinching Fastener Handbook (PDF)
Key Advantages Of Self-Clinching Fasteners
- Provide strong threads or attachment in metal as thin as 0.20 mm / .008″.
- May be installed using any parallel acting squeezing force.
- Provide high pushout and torque-out resistance.
- Do not require special hole preparation, such as chamfering and deburring.
- Reverse side of metal sheet remains flush – no swaged rim protrusion.
- No retapping necessary after application.
- Low installed costs.
- Can be installed using automated equipment for high volume applications. See PEMSERTER® presses.
Design For Assembly
Self-clinching fasteners help designers meet DFA parameters which include:
- Fewer parts to handle. Hardware such as washers, lock washers and loose nuts are no longer required in final assembly.
- Fewer assembly steps. Since the task of hardware installation is done during fabrication, the number of steps required for final assembly time is reduced.
- Less total assembly time. Fewer parts and less steps mean shorter assembly time.
Broadly defined, a self-clinching fastener (also known as clinch or captive fastener) is any device, usually threaded, that, when pressed into ductile metal, displaces the host material around the mounting hole, causing it to cold flow into a specially designed annular recess in the shank or pilot of the fastener. A serrated clinching ring, knurl, ribs or hex head prevents the fastener from rotating in the host material once it has been properly inserted. Thus, self-clinching fasteners become a permanent part of the panel, chassis, bracket, or other item into which they are installed. (View Animation)
Generally, self-clinching fasteners take less space and require fewer assembly operations than caged or anchor nuts. They also have greater reusability and more holding power than sheet metal screws. They are used chiefly where good pullout and torque loads are required in sheet metal that is too thin to provide secure fastening by any other method. Even if the sheet is thick enough to sustain tapping, it may actually be more economical to use self-clinching fasteners with gaugeable threads. They can be installed during fabrication or during final assembly to eliminate loose hardware. In fact, the use of self-clinching fasteners often will support a thinner sheet metal, and permit a real reduction in installed cost over the cost of other fastener designs. Because of their compact design and low profile, they provide for a neat appearance, too.
As a rule, a self-clinching fastener should be specified whenever a component must be readily replaced and where “loose” nuts and hardware wouldn’t be accessible. If the attaching “nuts” and “screws” can’t be reached after a chassis or cabinet is assembled, self-clinching fasteners can be installed during metal fabrication and can simplify and expedite component mounting and assembly operations, including those performed in the field.