Service HotlineWhen processing some disc parts, the mandrel is often used for positioning, and the nut is pressed on it. However, the ordinary nut cannot meet the requirements due to its small end face and poor flatness. The user needs to make the nut, and the cost is high due to single-piece production.
The existing machine screw structure is not conducive to assembly and automated production. The machine screw is in the form of a cylinder, the outer surface of the cylinder is provided with threads, and one end of the machine screw is provided with a notch. During installation, it is convenient to rotate the machine screw by the tool acting on the notch, so that the machine screw all enters the threaded hole and does not occupy the external space. However, the thread on the outer surface of the machine screw corresponding to the slot is easily deformed or scratched due to the external force of the tool and the threaded hole, which makes it difficult to screw in or disassemble, and reduces the versatility and interchangeability. affect product quality.
According to the development and evolution process of self-tapping screws, we believe that the main types of self-tapping screws are as follows: 1. Common self-tapping screw threads are self-tapping threads, also known as wide thread. The surface is mostly electroplated. 2. Self-cutting and self-tapping screws are called scraping ends of self-tapping screws in my country's standard. The threads are self-tapping threads or machine threads, and the cross grooves are also H type. There are several types of self-cutting self-tapping screws: cross recessed pan head self-cutting self-tapping screws, cross recessed countersunk head self-cutting self-tapping screws. Cross recessed countersunk head self-cutting self-tapping screws, hexagon head self-cutting self-tapping screws. 3. Self-extrusion and self-tapping screws (self-tapping locking screws) The threads of self-extrusion and self-tapping screws are generally machine threads, and self-tapping threads are rarely used. In the wrenching method, in order to ensure the use of high-speed automatic assembly wrenches, slotting is generally not recommended. The cross section of the screw of the self-extrusion self-tapping screw is triangular. So it is also called triangular thread screw. 4. Self-drilling and self-tapping screws (self-drilling screws) The threads of self-drilling and self-tapping screws are self-tapping threads according to Chinese, German and international standards. In the American ASME and SAE standards, the BSD self-drilling self-tapping screws are self-tapping threads, and the CSD self-drilling self-tapping screws are machine threads. Self-drilling self-tapping screws are not recommended for slotted and normal hex head. 5. Metal driving screws (metal tapping screws) The metal driving screws have multiple threads and special threads with a certain helix angle. Only the American standard has metal drive screws, and there are no Chinese and German standards. 6. Wallboard self-tapping screws (dry wall screws) Wallboard white tapping screws are special threads with horn head, cross groove (H type) and 60° profile angle, and the surface is mostly phosphate treatment (phosphating). 7. The cross groove of the fiberboard nail is Z-shaped, and the surface treatment is mostly electroplating. There are several types of fiberboard nails: countersunk head, double countersunk head fiberboard nails, pan head, pan head flange (with pad) fiberboard nails, semi-countersunk head, semi-countersunk head flange (with cushion) fiberboard nails. 8. Combination self-tapping screws Ordinary self-tapping screws, self-cutting self-tapping screws, self-drilling self-tapping screws, etc., and flat washers, elastic washers (including spring washers, elastic locking washers, etc.). 9. Others Self-tapping screw types High and low thread double lead self-tapping screws, coarse and fine thread (different pitch) thread self-tapping screws, threads coated with sealing material (fall resistance) self-tapping screws, various composite groove self-tapping screws, Other special self-tapping screws, etc. In short, there are many types of self-tapping screws. With the development of production, the advancement of technology, new materials, new structures, and new thread forms, new self-tapping screw products will continue to appear.
Flat washers are generally used in connectors, one of which is soft and the other is hard and brittle. Its main function is to increase the contact area, disperse the pressure, and prevent the soft texture from being crushed. The basic function of the spring of the spring washer is to give a force to the nut after the nut is tightened to increase the friction between the nut and the bolt! The material is 65Mn (spring steel), the heat treatment hardness is HRC44~51HRC, and the surface is oxidized.
At present, in the era of industrialization, rivets used in specific occasions, automobiles, and aviation industries can only rely on professional tools and equipment to complete the riveting method.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: waterproof sealing nuts, GB956.1 washers, support studs, turning parts and other products, we can provide you with suitable fasteners for you solution.
