The application relates to a
precision casting forming die for a
brake piston, which comprises a fixed die, an intermediate die, a movable die and an ejection
assembly, a
pressure casting is formed between the intermediate die and the movable die, and a material
handle is formed between the fixed die and the intermediate die; the material
handle comprises integrally-formed main
sprue waste and a runner waste, the ejection
assembly is used for ejecting the main
sprue waste towards the side of the intermediate die when the fixed die and the intermediate die are opened; one end of the runner waste, which is far away from the main
sprue waste, is provided with a clamping block, and a clamping groove matched with the clamping block is arranged on the fixed die. During the process of opening the fixed die and the intermediate die, the end of the runner waste close to the
pressure casting is limited on the fixed die, thereby being separated from the
pressure casting, the other end is not limited and is pushed towards the side of the intermediate die under the action of the ejection
assembly, the runner waste is deformed, thereby keeping most of the runner waste separated from the fixed die and the intermediate die, and finally an operator manually pulls down the runner waste so that the clamping block is separated from the clamping groove.