Inspection box

The inspection box is made of gray cast iron, usually a square of 100mm to 500mm, with a dimensional accuracy within 0.01mm. The relative planes are parallel to each other, and adjacent planes are perpendicular to each other. The allowable error is within 0.01mm.

The inspection method for square boxes is similar to that of ordinary cast iron square boxes. For square boxes with a side length of 300mm or less, 1mm measuring blocks are placed at each end of the inspected surface of the square box during inspection. The cutting edge ruler is placed on the working surface of the measuring block, and then the measuring block is used to test the plug at each inspection point. The difference between the size of the measuring block when it is just inserted and the size of the measuring blocks at both ends is the deviation between the two ends of the inspected point. This verification should also be conducted on several sections of the square box working face in the longitudinal, transverse, and diagonal directions. When the error directions of the straight lines measured at various positions are consistent, take the maximum value. When the error directions are not consistent, take the sum of the large positive and negative differences to obtain the flatness of the inspected surface plane.

The inspection box is mainly used for checking the parallelism and perpendicularity of components, as well as supporting workpieces during marking. It is generally a cube with the same side length.

Purpose of inspection box: The square box is mainly used for inspecting and marking the parallelism, perpendicularity, etc. of components. A square box is a hollow cube made of cast iron with six working faces, one of which has a V-shaped groove. The environmental conditions for square box calibration are normal temperature and humidity.

Requirements for inspecting the square box: Each working surface of the square box must be free of rust, scratches, cracks, dents, and other defects that affect the metrological performance. Non working surfaces should be sandblasted and painted, with chamfered edges. There should be signs on the inner wall of the square box, indicating specifications, dimensions, grade, factory number, and manufacturer name.