How to determine the machining allowance of machining? The size of machining allowance has a great impact on machining speed, quality and cost. Therefore, it is necessary to carefully determine the machining allowance of machining. As we all know, too much is not enough. The same is true for machining allowance. If the machining allowance is too large, it will not only increase the labor of machining and reduce the productivity, but also increase the consumption of materials, cutting tools and electricity, and increase the processing cost; If the machining allowance is too small, it can neither eliminate various surface defects and errors of the previous process, nor compensate the installation error of the workpiece during machining in this process, resulting in scrap. Therefore, machining allowance should be carefully selected.
There are three methods to determine machining allowance:
First, look-up table method. According to the machining allowance data provided in the relevant manuals, and combined with the actual production situation of the factory, the machining allowance is determined after correction. This method is widely adopted by all factories.
Second, empirical estimation. The allowance shall be determined according to the experience accumulated by the process personnel. Generally, in order to prevent scrap caused by too small margin, the estimated margin is always too large. It is often used in single piece and small batch production.
Third:analysis and calculation. According to the theoretical formula and certain test data, the factors affecting the machining allowance are analyzed and calculated to determine the machining allowance. This method is more reasonable, but it requires comprehensive and reliable test data and complex calculation. Generally, it is only used in factories where materials are very valuable or a few are produced in large quantities.
