Different measuring instruments are used for different steels, and online calipers are used for the detection of high-speed wire rod, round steel, steel pipe, rebar, hexagonal steel and octagonal steel. Angle steel square steel can use side length caliper, which is actually a kind of caliper; In addition, excellent talents, including H-beam and T-beam, can also use profilometer to detect surface defects and contours. Plate products usually use photoelectric width gauge and laser thickness gauge to detect the width and thickness, and there are also ray thickness gauges to detect the thickness of thin plates with high accuracy. There are also length measuring instruments and cutting measuring instruments used in the production line. All kinds of customized instruments escort the high-quality production of steel production line.