The square box is a hollow cube made of cast iron with 6 working faces. It is used for the inspection and marking of the parallelism and perpendicularity of the parts. One of the working faces has a V-shaped groove, which can be divided into cast iron according to the application. Line box, cast iron inspection box, used to inspect or scribe arbitrary angle lines of precision workpieces.

The environmental conditions for the verification of the square box are normal temperature and normal humidity.

Square box specifications(mm): 100,150,200,250,300,350,400,500, 600;

Accuracy of square box: generally a cube with a square of 100 mm to 500 mm, the dimensional accuracy is within 0.01 mm, the opposite planes are parallel to each other, the adjacent planes are perpendicular to each other, and the allowable error is within 0.01 mm. The square box standard in my country divides the square box into 6 levels, namely 000, 00, 0, 1, 2, and 3. This accuracy roughly corresponds to 1, 2, 3, 5, 7 of the flatness tolerance specified in GB1184-80. , 9, a total of 6 levels, in view of the fact that there is no commodity for sale in the 000-level square box, the regulations divide the accuracy of the square box into 5 levels, namely 00, 0, 1, 2, and 3.

cast iron square box

Technical parameters of square box:

1. Material requirements: high strength cast iron HT200-300, hardness: HB170-240;

2. Artificial annealing: annealing and aging treatment at a high temperature of 600-700 degrees in a tempering kiln;

3. Shovel scraping process: Manual scraping is an important process in the processing of cast iron square boxes. It determines the flatness error of cast iron square boxes and the number of contact points on the working surface. The 0-level square box has 25 points on each side. No less than 25 points in the range of ㎜ square; no less than 20 points in the range of 25mm square on each side of level 1 square box; no less than 16 points in the range of 25mm square on each side of level 2 square box ;The level 3 square box shall have no less than 12 points within the range of 25mm square on each side, and the four edges of the rear box shall be blunt after scraping;

4. Packaging requirements: mainly wooden packaging, try to use thick wood to cover the working surface of the platform for fully enclosed packaging, and the anti-rust measures on the working surface of the box in front of the packaging must be well-prepared, and have good moisture-proof, shock-proof, rust-proof and anti-corrosion measures. Measures to protect the slab, such as brutal handling, to ensure delivery to the site;

5. The working surfaces of the square box should not have rust, scratches, cracks, dents and other defects that affect the measurement performance. The non-working surfaces should be sanded and painted, and the edges should be chamfered. There should be a sign on the inner wall of the square box, and it should be marked with the size, the factory number of the grade, and the name of the manufacturer.

6. The cast iron square box is subject to regular weekly inspection according to the standard, and the inspection period can be 6-12 months according to the specific situation.