A square is a tool that has at least one right angle and two or more straight edges for drawing or examining a right angle, and sometimes for scribing. Applicable to the verticality inspection of machine tools, mechanical equipment and parts, installation and positioning, and scribing are important measurement tools in the machinery industry. It is characterized by high precision, good stability and easy maintenance.

The square ruler specifications are: 750×40, 1000×50, 1200×50, 1500×60, 2000×80, 2500×80, 3000×100, 3500×100, 4000×100, etc., cast iron flat rule product alias: square ruler , cast iron square ruler, inspection square ruler, rectangular square ruler, square square ruler, parallel square ruler, equal square ruler angle ruler and special flat ruler for machine tool guideway, workbench precision inspection, geometric precision measurement, precision component measurement, scraping process Processing, etc., is the benchmark for precision measurement.