Service HotlineWith the mass production of large-scale equipment, standardization, and the concept of lean production, it has become more and more important to improve the efficiency of the assembly stage. Nowadays, when assembling small equipment, power tools and automatic bolt supply devices are basically popular, but only for M3 and smaller However, large equipment is often fastened with M8 or larger diameter bolts, and it is still in the process of combining manual and air tools. Among them, the pre-installation of the flat and spring washers on the bolts is completely manual operation. When the bolts need to be tightened in large quantities, the shortcomings of low efficiency are particularly obvious, and the flat and spring washers are easy to be scattered when manually assembled, and there are mixed installations of different specifications. Problems such as less installation and missing installation will affect the processing quality.
Pedicle screws can be divided into four types: one-way short-tail screw, one-way long-tail screw, universal short-tail screw and universal long-tail screw. Pedicle screws can effectively complete the three-column fixation of the spine and are clinical The most widely used internal fixation method for the treatment of spine-related diseases. Due to the different types of pedicle screws, four different screwdrivers are required to complete the screw insertion. However, the implantation of pedicle screws is performed in a complex three-dimensional space, which has high difficulty and risk. Mis-implantation of screws may cause instability of the internal fixation frame in the early stage, and may cause false joint formation in the later stage. Therefore, in the process of spinal internal fixation, it is necessary to ensure the accurate implantation of pedicle screws is the key to the success of the entire spinal internal fixation, and the selected implanted instruments are particularly important.
The existing method of tightening large screws is generally 1. After the nut is screwed to the connected piece by hammering + nut angle method, use a casing to connect the lever arm of the wrench, or use a free hammer to hammer the plate handle, Rotate the nut an additional angle to obtain the required preload. This is not only a primitive and labor-intensive fastening method, but also has great limitations, such as limited space, or the screw itself is a rotating shaft and so on, it is difficult to use this method.
At present, there are two commonly used nut fixing methods, one is welding fixing: high energy consumption, the welding process easily leads to thread deformation in the nut, which requires re-tapping, which increases the cost, and for aluminum alloy and other materials, the welding process is poor, It is easy to produce welding defects and cannot achieve the function of fastened connection; the other is to pull riveting: in this method, the connection force of the nut is not strong, the reliability is not good, and it is not suitable for thin-walled profiles.
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.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: mechanical auto parts screws, blackened spring washers, national standard expansion screws, anti-loosening spring washers and other products, we can provide you with suitable fastening products piece solution.
