Oxygen cutting, mechanical cutting (cutting, sawing, grinding wheel cutting) and other methods are commonly used for cutting steel. Oxygen cutting process requirements: before gas cutting, should remove the steel surface of oil, rust and other debris, and leave a certain amount of space below. Large workpiece cutting, should start from the short side. When cutting the workpiece of different shapes on the steel plate, should be side by side by the Angle, reasonable arrangement, first cut the large pieces, then cut the small pieces; The first cut is more complex, the second cut is simple; The cutting of narrow strip plate adopts the method of cutting two long sides simultaneously to prevent side bending. The allowable deviation of mechanical cutting the allowable deviation of gas cutting the allowable deviation of the project the allowable deviation of the project the allowable deviation of part width, length ± 3.0mm part width, length ± 3.0mm edge missing edge 1.0mm cutting surface flatness 0.05t, but not greater than 2.0mm steel end perpendicularity 2.0mm, cutting depth 0.3mm, local notch depth 1.0mm.