The return pin (also known as the return rod or return pin) is a key guide component in injection and stamping molds. It is mainly used to ensure that the ejector system is accurately reset after demolding to avoid interference with mold closing.
Core function
Accurate reset:
After the ejector plate (Ejector Plate) completes ejection, the return pin contacts the mold core and forces the ejector mechanism to return to the initial position.
Guide protection:
Guide the ejector plate to move linearly to prevent deflection wear and extend the life of the mold.
Safety buffer:
Some designs contain a spring preloaded structure (Spring-Loaded Return Pin) to reduce reset impact.
Type and material
Standard type: cylindrical straight rod, hardness HRC52-56 (SKD61 or SUJ2 material);
Shoulder type: additional positioning step to prevent loose installation;
Plating treatment: chrome plating or nitriding on the surface to improve wear resistance.
Application scenario
Injection mold: must be equipped with the ejector system to ensure reset before mold closing;
Stamping mold: used for stripper plate guide reset.
The return pin is a basic component to ensure the continuous and efficient operation of the mold. Its accuracy directly affects production stability and product yield.