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.
Wood screws, one of which is a polished rod, the angle and pitch of the teeth of the wood screws and self-tapping are different. Self-tapping screws have high hardness, wide thread spacing, deep threads, and uneven surface, while wood screws are the opposite. Another difference is more obvious. Wood screws have no threads at the rear. Self-tapping screws are generally subject to heat treatment, and wood screws are not required. The concept of self-tapping screws is actually very general, because there are many kinds of them according to different head types. Use of wood screws: Similar to machine screws, but the thread on the screw is a special rib for wood screws, which can be directly screwed into wooden components (or parts).
When the rivet is riveted, it is often necessary to locate and fix the rivet. However, the common rivet positioning mechanism at present often has no way to effectively and quickly remove the restriction on the rivet after the rivet is fixed, which makes it difficult for the nailing mechanism to be inserted. Quickly drive the positioned rivets.
Process equipment for aircraft production (hereinafter referred to as tooling) is directly used for part forming and component assembly. In order to satisfy the loading and unloading of aircraft parts and components during the use of the tooling, the tooling generally adopts a structural form that is easy to disassemble as a whole. In the field of aircraft process equipment manufacturing, positioning pins are usually used to connect and position the detachable parts of the tooling. At present, this kind of locating pin is divided into two types: direct pull-out locating pin and tie-suspended locating pin.
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