The working surfaces of the magnetic square box must not have rust, scratches, cracks, dents, or other defects that affect the metrological performance. Non working surfaces should be sandblasted and painted, with chamfered edges. There should be labels on the inner wall of the magnetic square box, indicating specifications, dimensions, grade, factory number, and manufacturer name.

Execution standards and applications of magnetic square boxes:

The magnetic square box is manufactured according to JB/T3411.56-99 standard, made of HT200 material, and used for checking and marking the parallelism and perpendicularity of components; Magnetic square boxes are used to inspect or mark any angle line of workpieces, and can be made into various specifications and equally high magnetic square boxes and rectangular tubes according to user requirements.

Magnetic square box is used to inspect or mark any angle line of the workpiece, and is suitable for measuring and marking fixtures. Widely used for checking the parallelism and perpendicularity of components and supporting workpieces during marking, it is generally a cube or rectangular prism with the same side length. Various specifications and high magnetic square boxes and rectangular tubes can be made according to user requirements. Advantages of magnetic square box: The V-shaped groove has magnetic force, which can fix the measured workpiece and ensure accurate measurement.

For magnetic square boxes with a side length of 315mm or less, during calibration, 1mm measuring blocks are placed at each end of the inspected surface of the magnetic square box. A straight edge with a knife edge is placed on the working surface of the measuring block, and then a measuring block is used to test the plug at each inspected point. The difference between the size of the equivalent block group 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 magnetic square box working surface 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.