Extension Springs | Produced In Stainless Steel

DIN 17224 AISI 302 WERKSTOFF NO. 1.4310
Working temperature between -200 ºC and +250 ºC.
Produced in stainless steel for use in all environment. The stainless steel is rust-resistant.

Range A: (The A Range consists of springs with 5 digits, ie: "32200")

All dimensions and forces in accordance with DIN 2097 (Grade 2). DIN 2097 defines the force as the determining parameter. The number of coils may therefore vary and is consequently not stated for these ranges.

Range B: (The B Range consists of springs with 11 digits and 2 letters, ie: "E03600552000M")

For more information, see our FAQ page

Fn for stainless steel spring steel is approx. 0.88 x Fn for music wire.

Calculation of the initial force (F0):
The initial force F0 or the initial tension is for guidance only due to differing production processes.
F0 = Fn - (R * Sn). A rule of thumb is however that F0 is 10-15% of Fn.

For example, for stock number 32600, Fn = 237 N, R = 2,67N/mm og Sn = 75,70mm. F0 = 237N - (2,67N/mm * 75,70mm) = 237N - 202N = 35N

The calculation of spring force for a given length:
Calculation of spring force at a given length is: F0 + (travel * R).
For example, for stock number 32600 where R = 2.67 N/mm, the desired travel is 55 mm and F0 is approx. 35 N. 35N + (55mm * 2,67N/mm) = 35N + 147N = 182N

Range A: Closed German loops in accordance with DIN 2097, random angle.

Tolerance at loop height (LH) is from 0.8 to 1.1 * Dm. The loop position (X) is variable and the loops can therefore be turned in relation to one another. The diameter of loops may well exceed the external diameter of the body. The tolerance for deviations is determined based on the definition below.

Example: Stock number 32600 has a wire thickness of 2.5 mm. The external diameter is 18 mm, which produces a mean diameter of 15.5 mm. From the table above, we can determine how wide the loop must be. First we must work out the coil ratio using the formula Dm/d. The loop width can then be determined using the table above.
Coil ratio: 15.5 mm/2.5 mm = 6.2 mm
Loop width: 18 mm + (1.5 * 2.5 mm) = 21.75 mm

Range B: Loops in this range are closed loops without a specific loop shape and with a random angle. Every effort is made to keep the same external diameter as the spring body. However, the external diameter of the loop may vary.

Normally right-handed

Standard springs are not defined with a specific direction of wind. Depending on production, the springs may be produced either right or left wound. If you require a specific direction of wind a special spring must be produced.

If an extension spring with an exact value for one of the following parameters is required, springs must be custom-made:
- Loop type
- Loop height (LH)
- Loop position (X)
- Loop width (if the spring is to be incorporated into a tube)
- Opening at loop (m)
- Initial force (F0)