Die Spring Characteristics

Century Spring has designed and manufactures a complete line of industrial die springs. Generally used in die machinery, they are well-suited for many applications where high-static or shock-load stresses are required or when maximum cycle-life is important.

Hole and Rod Diameter

The die spring containment hole diameter sizes used in our online and print catalogs must be considered to eliminate possible spring-to-wall friction caused by heat, wear due to fabrication tolerances, and interference from the spring diameter growth due to compression. If the spring is long for its diameter, an internal supporting rod may be required to eliminate spring buckling.


Thermal effects are frequently ignored in spring failure or load-loss analysis. The maximum rated service temperature for chrome-alloy steel is about 440° F. The following table reflects the approximate load losses due to heat that can be expected with die springs.

Materials & Service Life

All of our die springs are fabricated from the most efficient wire cross section, which is rectangular with rounded corners. The oil-tempered die springs are offered for die sets and general use at a reduced cost. A very long service life may be expected from oil-tempered springs if their maximum deflection is held to about 25% of their length. The highest grade of electrically-furnaced, shot-peened and preset chrome-alloy steel die springs are offered for unsurpassed quality.


Die springs of oil-tempered material are available as unfinished only. A color coding system is employed for our chrome-alloy line for instant visual identification of the spring's work range and to prevent errors in spring selection and installation. The color coding is a light coating of water-based paint.

Chrome Alloy Color Code

  • Light Duty - Blue
  • Medium Duty - Red
  • Heavy Duty - Gold
  • Extra-Heavy Duty - Green

Chrome Silicon Color Code

  • Light Load - Green
  • Medium Load - Blue
  • Heavy Load - Red
  • Extra-Heavy Load - Yellow