What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
With the popularization of electrical equipment, the door cover that integrates the panel, the controller, the sealing and waterproof function and the appearance decoration has gradually been required for equipment matching. The head directly affects the appearance, and for kitchen equipment such as dishwashers, the fixing screws of the door cover are easily rusted in direct contact with the washing water, which urgently needs a door cover structure that is easy to disassemble but does not affect the appearance.
1. When the main body is large equipment, accessories need to be installed, such as sight glass, mechanical seal seat, deceleration frame, etc. At this time, a stud bolt is used, one end is screwed into the main body, and the other end is equipped with a nut after the accessory is installed. Since the accessory is often disassembled, the thread will be worn or damaged, and it is very convenient to use the stud bolt to replace. 2. When the thickness of the connecting body is very large and the bolt length is very long, stud bolts will be used. 3. It is used to connect thick plates and places where it is inconvenient to use hexagonal bolts, such as concrete roof trusses, roof beam suspension monorail beam suspension parts, etc.
At the beginning of the quality inspection process broadcast, we ordered the cross recessed screw and screw wire material into our production screw industry. For manufacturers in the screw industry, we must first detect the wire diameter of the screw wire and the material of the screw. Generally, the wire diameter of the screw is measured by a caliper and a measuring wire. Diameter size, whether it is the same as the size ordered by yourself. 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 production and sales process of cross recessed screws, 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. .
hand screw is a screw with a plastic head, and the user fixes the hand screw by turning the plastic head by hand. At present, a hand-tight screw is disclosed in the market publication number CN202203253U, which includes a plastic head and a screw rod, the plastic head and the screw rod are connected together, and the height of the plastic head is higher than that of ordinary screws, and the height is 11 cm. The screw of the hand screw is fixed in the plastic head by glue. After a period of use, the aging of the glue leads to the loosening of the screw and the plastic head. When the plastic head is stressed, the screw rod comes out of the plastic head, which affects the normal use of the hand screw.
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