(1) line cutting the workpiece blank size, according to the parts to determine the size, not too small. In general, cutting room should be located at the middle or leave blank blank edge is far not easily distorted position, usually blank margins should take about 10mm.
(2) where the cavity is larger or the long and narrow and complicated parts, to change the traditional solid sheet. Big box cavity, long and narrow cavity easy distortion part, the middle part should be cut. This quenching table in the small temperature difference. The stress is small, removal of the volume is small, the stress equilibrium will not be destroyed.
(3) in the permit, big box shaped cavity parts of the corner, should be appropriate to increase the process of round R, or will the corners of drilling, line cutting, reducing the stress concentration.
(4) on the convex parts in quenching, before the threading hole drilled in the convex block blank, so that the workpiece to maintain internal force balance in cutting, in order to avoid from the material distortion caused by cracking.