According to the head type, rivet nuts can be divided into hexagonal and round heads, as well as through-hole blind holes, and the distinction between flat head and countersunk head. The most primitive ones are actually flat heads. Flat head rivet nuts are riveted to the plate. There was a small step on the part, and later on occasions that were not suitable for this step, a countersunk rivet nut appeared. The reserved space for the flat head is a round space, and the reserved hole for the flat head nut is chamfered. Yes, it is a tapered surface. When the nut is riveted to the sheet metal, it is flush with the sheet metal, leaving no small step，blind rivet nut appeared later

The difference between countersunk rivet nuts and flat head rivet nuts

(1) Pressure riveting nut Preschool rivet nut, self-fastening nut, is a kind of nut applied to thin plate or sheet metal, with a round shape, one end with embossed teeth and guide groove. The principle is to press the embossing teeth into the preset holes of the sheet metal. Generally speaking, the aperture of the preset holes is slightly smaller than the embossing teeth of the pressure riveting nut. The flower teeth of the pressure riveting nut are squeezed into the guide groove by pressure, thereby Produce a locking effect.

(2) The countersunk head willow nut is also called "the gospel of the thin plate connection process". It changes the old method of the traditional process. When parts are installed on the thin plate, there is no need to tap the internal thread and no welding nut, which is firm and beautiful. , Convenient and fast, can be widely used in the assembly of electromechanical and light industrial products such as automobiles, aviation, railways, refrigeration, elevators, switches, instruments, furniture, decorations, etc.

The above is the basic difference between countersunk head rivet nut and flat head rivet nut.