Requirements for die-casting molds

① The entrance of the transverse sprue of a cold horizontal mold should generally be located at the upper part of the pressure chamber with an inner diameter of more than 2/3, to prevent the metal liquid in the pressure chamber from entering the transverse sprue prematurely under the action of gravity and starting to solidify earlier.

② The cross-sectional area of the transverse sprue should gradually decrease from the vertical sprue to the inner sprue. In order to expand the cross-sectional area, negative pressure will occur when the metal liquid flows through, which is easy to absorb gas on the parting surface and increase the vortex entrapment in the metal liquid flow. The cross-section at the outlet is generally 10-30% smaller than that at the inlet.

③ The transverse sprue should have a certain length and depth. The purpose of maintaining a certain length is to stabilize and guide the flow. If the depth is not enough, the metal liquid will cool down quickly. If the depth is too deep, the condensation will be too slow, which not only affects productivity but also increases the amount of return material used.

④ The cross-sectional area of the transverse gate should be greater than the cross-sectional area of the inner gate to ensure the speed of metal liquid entering the mold. The cross-sectional area of the main runner should be greater than the cross-sectional area of each branch runner.

⑤ The bottom sides of the transverse runner should be rounded to avoid early cracks, and a slope of about 5 ° can be made on both sides. The surface roughness of the transverse runner is ≤ Ra0.4 μ m。