For tool steel, its stability is mainly determined by the thermal fatigue toughness and strength of steel. Therefore, thermal stability, good mold steel fatigue must have good toughness and high strength (wet strength) a good fit. There should be welded flat work surface rust, the appearance of defects scratches, bumps and other effects used.

Work surface should not have sand holes, pores, cracks, slag and casting defects such as shrinkage. Each sand casting surface should be completely removed, and the surface smooth, painted solid, each side should be amended tax blunt. In the welding plate, welded on opposite sides of the plate, the installation should be set up, threaded cylindrical bore hole or handle or lifting position. Should be set up to consider lifting position to minimize the distortion caused by lifting. Tablet should be handled by the stability and demagnetization.

Spiral Pipe thermal stability is strong, spiral reason is widely used, still has its unique advantages. Generally, the spiral is very good bending properties, as in the production process, is to be bent at least 180 degrees, and a surface coil can not crack. Not only it is better bending performance, reverse bending performance is also good. Reverse bending test apex diameter bending test should be more than one bar diameter increases. This step experiment: first forward bend 45 degrees, the reverse bend 23 degrees, 23 degrees after the reverse bending. Moreover, after the reverse bending test, spiral surface is still no cracks.

General into the surface using a spiral steel pipe are no cracks, some of the scars or traces of folding. While the spiral projection surface can be allowed, but not more than the height of the transverse ribs, and other defects on the coil surface and a depth not greater than the height dimension of the portion where the tolerance.