What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
Procurement and sales in the testing process know that the quality of screws is manufactured, not detected, but in manufacturing, we must try our best to make them as good as possible. But it is unlikely to be completely error-free and error-free. We all know that errors are unavoidable and can only be approached infinitely. Therefore, at this time, the quality inspection of the screw is required to improve the quality of the screw. At the beginning of ordering from screw wire material into the production of screw industry manufacturers, you must first check the wire diameter of the screw wire and the material of the screw. Generally, the wire diameter of the screw is measured with a caliper to measure the size of the wire diameter, whether it is suitable for self-ordering. Same size. After testing these, it is the testing in the production process, starting from the head of the screw, to determine the size of the head, the opposite side of the head, the diagonal angle, the depth of the cross groove, the tolerance range of the screw, and so on. These are checked with calipers. In the inspection of all aspects when rolling teeth, the main thing is whether the thread can pass the pass and stop gauge, and whether the screw thread can pass the gauge and stop. Next is the electroplating measurement problem. After electroplating, whether it meets the requirements of environmental protection and whether it can pass the time required by the salt spray. Tools include environmental testing machines and salt spray testing machines. In short, in the process of screw production and sales, there must be necessary tools to detect the quality of screws. The summary should be summarized as follows: calipers, hardness testers, salt spray machines, environmental testing machines, pass and stop gauges, etc. When producing and selling screws, there will be a screw specification and screw model. With the screw specification and screw model, we can understand what specification screw and what size screw the customer needs. Many screw specifications and screw models are based on national standard specifications and models. Generally, such screws are called ordinary screws, which are generally available on the market. There are some non-standard screws, which are not based on the national standard specifications, models and sizes, but are customized according to the standards required by the product materials. There is no stock in the general market at all. In this way, it is necessary to make drawings and samples.
The pin, also known as the pin, has a simple structure and is easy to assemble and disassemble. It is widely used in various fixed connections. The pin is mainly used to fix the relative position between two parts, also used to connect parts, and can transmit a certain load. , At present, the pins on the market generally have the problems of being easy to loosen and fall off.
The slotted nut needs to be fixed with a cotter pin through the slot of the slotted nut, and the cotter pin must pass through the middle of the screw to fix the slotted nut. Usually, both ends of the screw need to be drilled, the diameter of the hole and the size of the slotted nut. The width and depth of the slot determine the size of the cotter pin. When the selected screw, cotter pin and slotted nut are relatively matched, the nut is fixed by the screw, so that the slotted nut does not loosen. This hexagonal slotted nut has the characteristics of high strength and is not easy to loosen when subjected to vibration. It is mainly used in occasions with vibration and shock, such as front and rear axles of automobiles, lifting equipment, presses and die-casting machines.
The circuit board is often the circuit board that plays a major role in electrical equipment, and the main electrical components of the circuit are often integrated on the motherboard. For single-layer circuit motherboards, rivets are used on the circuit motherboard in order to make the components more firmly fixed on the pcb board. In the prior art, the rivets are all set on the circuit board by an automatic riveting machine, which is controlled by an internal program to automatically complete the rivet-setting operation. This internal program is pre-set. If you need to rivet different motherboards, you must change the internal program. If you need to temporarily rivet a circuit board, it will be cumbersome to change the program again. Moreover, this kind of automation equipment is produced on a large scale and is not suitable for temporary operations.
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