Precision casting when pressed reasonable design with stripping mechanism, in order to ensure correct parts geometry, generally the surface not to slope. However, when pressing without pulling the design mechanism, the angle of the casting is usually considered when the casting surface is perpendicular to the parting surface. Doing so facilitates the extraction of the casting from the mold. It can also reduce the friction between the casting and the mold, and the deformation and damage of the casting mold.
For the machined surface and wall thickness is less than 5 mm of processing on the surface of the slope, can be used to increase the casting wall thickness in the form of making. For wall thickness in 5 ~ 10 mm of machining on the surface of the slope, can be used to increase and decrease the casting wall thickness in the form of the combination of make.
For wall thickness is more than 10 mm of processing on the surface of the slope, made in the form of available reduce casting wall thickness. For castings with holes and slots, should regard the length of the hole and groove depth given slope. For deep small holes, because earlier core-pulling, die material for its hold force is small, so no draft angle.