Springs and Rubber Pads Used in Dies

A spring is a machine element that stores energy when stretched and, when released, returns the same amount of energy that was spent stretching it.

The springs most commonly used in die-making are compression, tension, and torsion springs. The wire cross-section used to make springs is circular, square, or rectangular. Springs are generally used in dies with pressure plates for piercing, blanking, bending, drawing, and similar operations.

Springs are also used in stop/locating systems and other advancing mechanisms, such as in ejector-pin or ejector-plate molding processes.

In the image above, we see circular cross-section compression springs for small-tonnage dies and square or rectangular cross-section compression springs for medium-tonnage dies.

The figure above shows circular cross-section tension and torsion springs.

More detailed information can be obtained from the “Turkish Standards Institute Publications TS 1440, 1441, 1442, and TS 1443”.

The tables above give the dimensions and compression force for circular cross-section springs up to 16 mm in diameter and square cross-section springs up to 50 mm in diameter.

Rubber or Hard Rubber Pads

In low-tonnage, low-production dies for piercing, blanking, bending, drawing, and similar operations, rubber-faced strippers or pressure plates are used. Likewise, rubber die elements used as the female die in bending dies or as the punch in bulging dies deform easily and can return to their original shape when the die opens.

The figure above shows a rubber die element used as a pressure and stripper plate along with its main dimensions.

Additionally, the table below gives the dimensions and pressure force of the rubber pressure plates used in piercing dies.