Basic square box

The basic square box is used for measuring and inspecting the parallelism and perpendicularity of mechanical parts in the three-dimensional marking of fitters.

The basic square box is manufactured according to the JB/T3411.56-99 standard,made of HT200 material,for the inspection and marking of component parallelism and verticality.

Basic box specifications:(mm)100 150 200 250 300 350 400 500 600.

The accuracy of the basic square box is divided into three levels:1,2,and 3.

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

The use of basic square boxes:

During calibration,1mm measuring blocks are placed at both ends of the inspected surface of the basic square box.A straight edge is placed on the working surface of the measuring block,and then measuring blocks are used to test the plug at each inspected point.The difference between the size of the equivalent block group when just inserted and the size of the measuring blocks at both ends is the deviation between the inspected point and the two ends.This calibration should also be carried out on several cross-sections of the square box working surface in the longitudinal,transverse,and diagonal directions.When the error direction in the measured straight lines at each position is consistent,the maximum value is taken.When the error direction is inconsistent,the sum of its large positive and large negative differences is taken as the flatness of the tested surface plane.Application of casting square box:mainly used for inspecting and marking the parallelism and verticality of components.A cast square box is a specific six working face cavity cube made of cast iron or steel,with a V-shaped groove on one of the working faces.