Metal processing inspection standard

　　What is the inspection standard for metal processing

　　1. Basic principles:

　　The acceptance method used should only accept workpieces that are within the specified dimensional acceptance limit. For workpieces with matching requirements, the size inspection should comply with Taylor's principle, and the effective size of the hole or shaft must not exceed the maximum physical size.

　　Note: Taylor's principle is that for holes and shafts with matching requirements, the actual local size and shape errors must be controlled within the dimensional tolerance zone (shaft minus hole plus).

　　2. Principle of minimum deformation:

　　In order to ensure the accuracy and reliability of the measurement results, the deformation caused by the influence of various factors should be minimized.

　　3. The principle of the shortest dimension chain:

　　In order to ensure a certain measurement accuracy, the links of the measurement chain should be minimized, that is, the measurement chain should be the shortest (to reduce the accumulation of measurement errors).

　　4. The closed principle:

　　In the measurement, if the closed condition can be satisfied, the sum of the interval deviation is zero, which is the closed principle.

　　5. The principle of uniform benchmark:

　　The measurement standard should be consistent with the design standard and process standard.