D Series Extension Coil Spring

Specifications

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How to choose Extension Coil Springs

Points to check when selecting, with the values for this product (D Series Extension Coil Spring).

1. 1. Select the spring rate from the required load

   The operating load equals the initial tension plus the product of the spring rate and the extension. Calculate whether sufficient force is produced both at installation and at maximum extension. Listed spring rates range from 0.128 to 16.31 N/mm, and they vary widely with wire diameter and number of coils even at the same outer diameter.

2. 2. Operate within the maximum allowable load and length

   Extending beyond the maximum allowable load or maximum allowable length can cause permanent deformation (set) or damage to the hooks. Confirm that the load and length at maximum stroke are below the allowable values and that there is sufficient margin.

3. 3. Free length that fits the installation space

   Free length is the distance between the inner edges of the hooks under no load. It must be shorter than the spacing of the mounting holes or pins. Because initial tension applies load from the moment of installation, this must also be considered. Listed products range from 14.5 to 500 mm, and long coil products can be cut to adjust the length.

4. 4. Determine outer diameter and wire diameter based on fit

   The outer diameter is determined by whether it fits through the hole or the clearance inside the housing. For a given outer diameter, a thicker wire diameter produces a stiffer spring, and a thinner wire diameter produces a softer spring. Listed products have outer diameters of 2 to 34.5 mm and wire diameters of 0.1 to 3.2 mm.

5. 5. Select the material for the environment

   SUS304WPB offers excellent corrosion resistance and is suitable for humid or wet environments. Piano wire SWP-B has high strength but is prone to rust, so check whether surface treatment is applied. The operating temperature range also depends on the material, and an example for SUS304WPB products is -30 to +200 °C.

6. 6. Check hook shape and orientation

   The end shape, such as round hook or reverse round hook, affects compatibility with the pin or hole being engaged and determines the orientation of the hooks at both ends. Damage tends to concentrate at the base of the hook, so select a shape that avoids excessive bending when hooked.

This guide was written by AI based on the listed products' documents and specification items.

About Extension Coil Springs and all products

Description

Cold-formed extension coil springs. Wire diameters of 0.1 to 0.4 mm use SUS304WPB; 0.5 to 2.5 mm use SWP-B piano wire. Operating temperature range: -30 to +200 °C for SUS304, -30 to +80 °C for SWP.

FAQ

Q. How should I select the wire diameter and material for the D Series extension coil spring?

A. Wire diameters of 0.1 to 0.4 mm use SUS304WPB, and 0.5 to 2.5 mm use SWP-B piano wire. The available wire diameter range is 0.1 to 2.5 mm.

Q. What is the operating temperature range of the D Series extension coil spring?

A. For SUS304, the range is -30 to +200 °C. For SWP (SWP-B piano wire), the range is -30 to +80 °C.

Q. What are the features and main applications of the D Series extension coil spring?

A. It is manufactured by cold forming and features reverse round hooks and low-temperature stress relieving. Its main application is tension holding in small equipment.

Written by AI based on the content of the source documents.

Source documents

• Catalog SUPER SPRING 総合カタログ 40 pages Open page 39