Maximum fire limit tolerance and fit

2022-07-23
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Limits, tolerances and fits

mechanical parts shall be manufactured so that they can be interchanged. In other words, any part of a machine or a mechanical device must be made into a certain size and shape so that it can be installed on any other machine or mechanical device of the same type. In order to make the parts interchangeable, the size of each part should be made to fit well with its mating parts

limit: the limit is the maximum and minimum value specified for a certain dimension. For example, if the nominal diameter of a hole is 25.4mm (one inch) and its limit dimension is 25.375/25.425 (0.999 inch/1.001 inch), any part not greater than 25.425mm (1.001 inch) and not less than 25.375mm (0.999 brand popularity is further increased) inch is qualified

tolerance: the difference between the upper and lower limits of the limit is called tolerance. If the maximum limit is 25.425mm (1.001 inch) and the minimum limit is 25.375mm (0.999 inch), the tolerance is 0.05mm (approximately 0.002 inch). There are several different ways of showing tolerances on drawings

fit tolerance and machining allowance: fit tolerance is mainly used for fitting, such as the fit between hole and shaft. The fit tolerance is an amount deliberately set aside between the maximum limits of the fitting parts so that the two can achieve the required fit. Machining allowance is the metal layer that is cut off when machining a surface. In addition to "design tolerance", there is "process tolerance". If a surface under processing needs to be processed by one or more processes, the processing accuracy specified for this surface is called process tolerance. The size of machining allowance depends on the method used to manufacture the blank. The production planning staff can clearly realize that the requirements and expectations of the organization are different, and the methods adopted are also different

fit: in mechanical manufacturing, many parts have important close relationships. There are some assembly 7. The self built powerful experimental database work should be completed manually. Fitting can be divided into sliding fitting, rotating fitting, pressing fitting and cold shrinking fitting. Destroy exchange servo controller (end)

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