Service HotlineAt present, with the continuous improvement of microwave plasma chemical vapor deposition technology, researchers hope to obtain more excellent products by increasing the microwave power. During the use of the three screws, it is necessary to continuously adjust the length of the pins extending into the rectangular waveguide to make the reflected power of the system reach the minimum value and improve the stability of the system. Since the length of the three screws extending into the waveguide needs to be continuously adjusted with the change of the input power, and the adjustment state of the three screws cannot be recorded after the adjustment is completed, repeated adjustment is still required in the subsequent work, resulting in a time-consuming adjustment process. long and low work efficiency. Especially under high power conditions, the traditional three-screw dispenser has a high risk of microwave leakage. When manually adjusting, the human body is exposed to microwaves for a long time, which has certain potential safety hazards.
Screw (English a screw) refers to the parts used in construction machinery. It is a kind of threaded parts with sharp ends such as nails, small cylindrical or conical metal rods, with grooved or dimpled heads, and used alone. . The detection of the screw should start from the wire of the screw. The quality of the precision screw is directly related to the wire that produces the screw. A good screw wire will open the screws more beautifully. What screw head burst, what thread is bad. Good screw wires generally do not find this situation.
Spring washers are widely used in the load-bearing and non-load-bearing structures of general mechanical products. They are characterized by low cost and easy installation. They are suitable for parts with frequent assembly and disassembly. Quick and easy automatic selection of washers is included, but the anti-loosening ability of spring washers is very low! Especially in European and American countries that require high reliability, the adoption rate is extremely low, especially the important load-bearing structural connection parts have long been abandoned. Our country still has some applications in the military industry, but it has been improved to stainless steel. Steel spring washers have long been banned in CASC! It is also said to be very unsafe, because there are two reasons: 1 is circle rise and 2 is hydrogen embrittlement.
Self-tapping screws were introduced into the industry in large numbers in 1914. The earliest design (essentially imitating a wood screw) was a thread-forming screw made of hardened steel with an A-ended end, mainly used to connect sheet metal channels for heating and ventilation systems. Therefore, it is also called: sheet metal screw. By the end of the 1920s, with the widening of the market and new applications, emphasizing new designs, its application performance was widely improved. The following introduces the four different stages of the development of self-tapping screws in 40 years: thread forming self-tapping screws, thread cutting self-tapping screws, thread rolling self-tapping screws and self-drilling self-tapping screws. 1. Ordinary self-tapping screws (thread forming self-tapping screws) Ordinary self-tapping screws are a direct product of early sheet metal screws. The principle is: when screwing it into a prefabricated hole, the internal thread connected to the screw is formed by the displacement of the material around the hole and the material is pushed into the space between the threads. 2. Self-cutting self-tapping screws (thread cutting self-tapping screws) Because ordinary self-tapping screws are formed only in very thin threads. And it can be easily realized on materials with good toughness. Develop and expand the use of self-tapping screws to thicker sections and harder, brittle and other materials with poor deformability. In this way, the self-cutting self-tapping screw is developed: a cutting groove or cutting edge is machined at the end of the screw shank. When this kind of screw is screwed into the prefabricated hole, the screw acts as a tap and actually cuts out the thread that connects with itself. 3. Self-Extrusion Self-Tapping Screws (Thread Rolled Self-Tapping Screws) In the early 1950s, fastener engineers began to recognize the potential advantages of self-tapping screws as structural rather than just lightly loaded attachments. This has led to the development of a new self-tapping screw thread rolling self-tapping screw (self-extrusion self-tapping screw). According to the design principle of cold forging taps, the thread and end are specially designed for this kind of screw, so that the screw can be formed by applying intermittent and periodic pressure on the crest of its thread instead of on the side of the entire thread. Internal thread for connection. By concentrating and limiting the forming pressure, the pressurized material next to the hole is made to flow more easily and to better fill (squeeze) into the flanks and roots of the thread of the self-tapping screw. Since the frictional resistance of screwing in is much lower than that of ordinary self-tapping screws, threaded rolling self-tapping screws (self-extrusion self-tapping screws) can be screwed into thicker sections. At the same time, it has better screw control and tightening torque, and greatly improves the connection strength and overall firmness. The engineering standard of this kind of self-tapping screw stipulates that the selection of materials, the mechanical properties of heat treatment and the working performance should be strictly controlled. 4. Self-drilling and self-tapping screws (self-drilling screws) People have done statistics: Among the ten expenses that constitute the total assembly cost, the highest one includes the processing of holes. In practical applications of self-tapping screws, prefabricated holes need to be processed. Moreover, in order to make the prefabricated holes have good effect in practical application, the size of these holes must be controlled within a fairly strict range. In the early 1960s, self-drilling and self-tapping screws appeared. A major step forward in reducing assembly costs by eliminating the need to machine prefabricated holes. In general, self-drilling and self-tapping screws realize drilling, tapping and tightening in one operation. These are the four main stages of self-tapping screw design and development. In addition, two newly developed products are also worthy of introduction. Both are screws with a special thread type. One is designed for plastic and other low-strength materials; the other is used in the construction industry to connect cement wall panels, so it is also called wall panel self-tapping screws.
With the continuous improvement of road facilities, guardrails are set up in the middle of the roads in most cities at the separation of the upper and lower lanes. At the same time, guardrails are also set up between the motor vehicle lane and the non-motor vehicle lane. The bottom of the guardrail column is set with a base, and the base is usually made of If the steel nail is fixed, the deformation hole should be drilled on the asphalt road first, and then the steel nail should be knocked into the deformation hole. Because the outer wall of the steel nail is cylindrical, the friction force on the ground is small, and the guardrail is affected by the deformation. When the external impact force occurs, the steel nails are easily detached from the asphalt road, making the road guardrail lose its fixation. In some places, expansion screws are used to fix the railings, but during the tightening process of the expansion screws, the expansion pieces are opened by the force of the ejector rod, and the opening angle is small. Limited, the railing will still fall down when subjected to a large impact. Therefore, it is necessary to design a special screw for fixing the railing on the asphalt road.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: American flat washers, extended screw screws, hexagon socket head screws, aluminum rivet nuts and other products, we can provide you with suitable fasteners. Firmware Solutions.
