Mian die pin is a push rod.In order to facilitate the parts to fall off from the mold, polishing is used to reduce the roughness between the parts and the mold. At this time, a jacking rod is needed to ejection the parts from the mould,and must be keep less surface damage for screw parts. it is suitable for ejecting parts have precision and surface requirements,similar parts and support needle, flat thimble, pipe, etc., according to the different parts of the need to choose. it is the most common parts of screws parts open die ejecting.