Non standard step screw knurled screw flat head knurled thumb screw M2 M3

"Historical Editing Broadcast of Screws
In 1986, our country formulated a new standard for standard components, commonly known as the new standard in business. The most commonly used ones include GB5780, GB5781, GB5782, GB5783, and GB5784. GB5780 is a hexagonal head coarse stem half tooth screw with an accuracy level of C grade product, which can be replaced by GB5782 (GB5782 is a hexagonal head coarse stem full tooth screw with an accuracy level of A and B.) GB5781 is a hexagonal head full tooth screw with an accuracy level of C grade product. GB5783 can be used instead (GB5783 is a hexagonal head full tooth screw with accuracy levels of A and B). GB5784 is a hexagonal screw with thin stem and half tooth"

High strength hexagonal head bolt combination screws are mainly used for steel structures, such as railway and highway bridges, boiler steel structures, industrial factories, high-rise civil buildings, tower and mast structures, lifting machinery, and steel structures that require the use of friction type high-strength bolt combination screws. Its characteristic is that the bolt, also known as the bolt, has an additional dodecagonal body at the end. When installing, a special electric wrench must be used, which has two socket heads on top and bottom, one on the hexagonal body of the nut and the other on the decagonal body of the outer hexagonal screw. When tightening, apply a clockwise force to the nut and an equal counterclockwise force to the dodecagonal body of the bolt, so that the neck between the end of the outer hexagonal screw and the dodecagonal body is subjected to torsional shear until the neck is cut off, and the installation is completed. This type of high-strength external hexagonal screw is a one-time screw that cannot be removed after installation.

The production process of riveted nuts is basically similar to that of other screws. It's just that the screws are made with screw drivers, and the nuts are made with nut drivers. Let me introduce the production process of rivet nuts for everyone. 1. First, we need to determine what material the rivet nut is made of, so that we can use what material to produce it. Knowing what materials and materials to use, we can buy screw wires. 2. Determine the specifications and types of rivet nuts, and check their size and length. How big is the screw wire used in this way. After determining the materials, materials, specifications, and types, we need to see if they are commonly used rivet nuts. If so, there must be corresponding molds in the factory. If not, if it's non-standard, then we have to order the mold. After everything is ready for production, the shape of the rivet nut, which is the appearance, must be punched using a nut machine pier. After the pier is punched out, use a machine that taps the nut teeth to perform tapping treatment on it. 6. After tapping the thread, electroplating treatment is carried out. Stainless steel rivet nuts do not require electroplating, they only need to be cleaned. To electroplate other colors, you need to go to a professional electroplating manufacturer for electroplating treatment.