For mold base, generally, if the shape of the forging is relatively simple, the lower die of the die is usually used as the main cavity to standardize the model, and the upper die can usually be simpler or even use a flat anvil. If the shape of the forging is complex and the parting surface is set in the middle, the cavity needs to be designed for both the upper die and the lower die. Generally speaking, the upper and lower dies(mold base) are used to mold the forging. The lower die usually plays a main role and the upper die is auxiliary. However, there are special cases. If the lower die molding is not ideal, the upper die can be used as the main cavity, because reverse extrusion forming will be easier. The most important thing is to see the shape of the forging.
