Collection: Die Springs

Die springs are compression springs made from rectangular wire in chromium alloy steel. They deliver very high forces in a small space and are built for dynamic use in stamping and forming tools. Over 1,300 sizes in three series: ISO 10243, ISO D and Raymond® NAAMS, for hole diameters Dh from 9.5 to 63 mm and free lengths L0 from 25 to 305 mm. The colour shows the load class within a series. Choose series and colour, then filter on Dh, Dd and L0. Use s1 and F1 for frequent movement and sn and Fn for static load.

Series
Colour and load class
Hole ø Dh (mm)
Rod ø Dd (mm)
Free length L0 (mm)
Force F1, dynamic (N)
Spring rate c (N/mm)
Force Fn, static (N)
Dd Dh L0
Symbols
DhHole or sleeve diameter Dh the spring fits into (mm)
DdRod or guide diameter Dd that fits inside the spring (mm)
L0Free length L0, unloaded (mm)
cSpring rate c, force per mm of travel (N/mm)
s1Recommended travel s1 for dynamic use (mm)
F1Spring force F1 at the dynamic travel s1 (N)
snMaximum travel sn for static use (mm)
FnSpring force Fn at the static travel sn (N)
Colour code per series
Load classISO 10243ISO DRaymond® NAAMS
Extra lightLight green30 / 50 %
LightGreen25 / 35 %Green25 / 40 %
MediumBlue20 / 30 %Blue25 / 40 %Blue25 / 40 %
Medium-heavyRed20 / 30 %
HeavyRed15 / 25 %Red20 / 30 %Bronze15 / 25 %
Extra heavyYellow15 / 20 %Yellow17 / 25 %Green15 / 20 %
Ultra heavyGrey10 / 15 %

The colour shows the load class within one series. Raymond® and ISO colours are not interchangeable. Percentages show the typical travel s1 (dynamic) / sn (static) as a share of the free length L0.

Showing 1325 of 1325 die springs
Part No. Series Colour Hole øDh · mm Rod øDd · mm LengthL0 · mm Travels1 (dyn) · mm ForceF1 (dyn) · N Stock Price Ex. VAT
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How to choose a die spring

1
Installation space

Set the hole diameter Dh, the rod diameter Dd and the free length L0 you have room for.

2
Travel

Add the preload to the working stroke. The total is the travel the spring has to take.

3
Force

The force is roughly F = c × s, where c is the spring rate and s the total travel.

4
Operating conditions

For springs that move regularly, use the dynamic values s1 and F1. The static values sn and Fn apply to constant loads or springs that are only used now and then.

5
Series and colour

Choose the series first, then compare installation dimensions, travel and force. Never choose by colour alone.

The series
ISO 10243
ISO 10243 is the international standard for die springs in stamping and forming tools. Four load classes: green, blue, red and yellow.
ISO D
ISO D uses the same colour code as ISO 10243 and adds two classes: light green (extra light) and grey (ultra heavy).
Raymond® NAAMS
Raymond® NAAMS die springs have their own colour code: blue, red, bronze and green.
Long service life

Service life depends mostly on travel, operating speed, guidance, installation and temperature. For reliable operation:

  • Use several springs with a smaller deflection each, rather than a few springs close to their limit.
  • Guide long springs on a rod, in a hole or both.
  • Make sure the contact surfaces are flat and parallel.
  • Never compress the spring to solid length.
  • Do not mix series, lengths or load classes in the same tool.
  • Replace all springs that share the same load at the same time.
Material and temperature

Die springs are wound from rectangular wire in high-strength chromium alloy steel, made for dynamic use under high loads. At high temperatures the force and service life drop, so always stay within the travel limits and the operating temperature of the application.

Frequently asked questions
What is the difference between a die spring and a standard compression spring?
Die springs are made for very high forces in small spaces. The rectangular wire carries a high load with comparatively short travel.
Can I choose a die spring by its colour alone?
No. The colour only shows the load class within a series, and Raymond® and ISO use different colour systems. Always compare installation dimensions, spring rate, travel and force.
How many die springs do I need?
Divide the total force you need by the force of one spring at the working stroke. Round up and spread the springs evenly in the tool.
What is the difference between dynamic and static travel?
Dynamic travel s1 is for springs that are compressed again and again. Static travel sn is for springs under constant load or used only occasionally. For frequent cycling, keep within s1.
Why should all die springs in a tool be replaced together?
Springs in the same tool go through the same load cycles. If you replace only one, the force is spread unevenly because the old springs may already have settled or fatigued.
Need a spring that is not in the table, or help choosing? Contact us