Also known as the rivet nut, pull the cap, and instantly pull cap, all kinds of sheet metal for fastening areas, pipes and other manufacturing industries, is currently widely used in the automotive, aviation, railway, refrigeration, elevators, switches, instruments, furniture, decoration and other electromechanical assembly and light industrial products. To solve the sheet metal, thin fusible pipe weld nuts, tapping within easy slip teeth and other shortcomings of the development, it does not attack the internal thread, no welding nut, firmly riveted high efficiency, easy to use. Rivet nut types: flat head hex head half hex rivet nut with through-hole, blind hole, knurled and no knurled. Overview riveting nut rivet nuts can riveted on a single sheet, you can put two pieces of sheet metal riveted together, both rivets, but also a nut; also applies to only one side of the closed-shaped workpieces operation. In addition, the need for light metal workpiece material threaded connections, steel rivet nut is compact, easy to use screw sets. Rivet nuts are widely used in shipbuilding, vehicles, aviation, electronics, instrumentation, metal cabinets, elevators and other sectors of the plate connection, easy to operate, reliable connection, beautiful, low efficiency. Rivet nut deformation similar cylindrical workpiece deformation or bulging bureaucracy, generally bulging bulging coefficient represents the degree of deformation. Because rivet nut is deformed under the application of an axial pressure at both ends, the forces than the inner cylindrical workpiece or tube material is subjected to radial pressure bulging better. After riveting riveting nut, will shorten the length of its plastic shrinkage of its material and size. To prevent bulging coefficient exceeded the allowable value caused bulging cracks, must control its shrinkage.