There are three methods for determining machining allowance in metal machining

Allowance has a large impact on the speed, quality and cost of metal processing. Therefore, the machining allowance must be carefully determined. We all know that too much is too much. The same is true for machining allowances. Excessive machining allowance not only increases the amount of labor in processing and reduces productivity, but also increases the consumption of materials, tools and electricity, increasing the processing cost. If the machining allowance is too small, it can neither reduce various surface defects and errors in the previous process, nor compensate for the installation errors of the workpiece in this process, resulting in waste products. Therefore, the machining allowance should be chosen carefully.

There are three methods of determining machining allowances in metalworking:

1. Look-up table method. According to the machining allowance data provided by the relevant manuals, combined with the actual production situation of our factory, the machining allowance is determined after correction. This is a widely used method in various factories.

2. Empirical estimation method. The margin is determined based on the experience accumulated by the technicians themselves. In general, the estimated excess is always too large to prevent the excess from being too small to generate waste. Usually used for single piece and small batch production.

3. Analysis and calculation method. According to the theoretical formula and certain experimental data, the factors affecting the metal machining allowance are analyzed and calculated, and the machining allowance is determined. This method is reasonable, but requires reliable experimental data and is computationally complex. It is generally only used in factories with expensive materials or a few large-scale production factories.