For precision parts machining the main dimensional requirements are as follows.

1. for example, what is the cylindrical diameter? All have strict requirements, plus or minus the error within the specified requirements to be qualified parts, otherwise are not qualified parts.

2. The length, width and height also have specific strict requirements, positive and negative errors are also specified, for example, an embedded cylinder (take the most simple basic parts for example), if the diameter is too large, more than the error allowed within the range, it will cause, can not be inserted into the situation, if the actual diameter is too small, more than the error allowed negative lower limit, it will cause inserted too loose, not solid problems occur.

These are unqualified products, or the length of the cylinder is too long or too short, beyond the error allowed, are unqualified products, are to be scrapped, or re-processed, which will inevitably cause an increase in costs. Precision parts processing requirements is in fact the main size problem, must be in strict accordance with the other plus drawings for processing, processing out of the actual size will certainly not be the same as the theoretical size of the drawings, only, as long as the processing size within the error tolerance is qualified parts, so, precision parts processing requirements is in strict accordance with the theoretical size for processing.

Second is the advanced precision parts processing equipment and testing equipment, advanced processing equipment makes the processing of precision parts easier, higher precision, better results.