Tension Springs
A tension spring (or a pull spring) is best suitable to the case where tension is applied.
Tension springs are made of various materials in various machining methods to allow usage under various conditions and environment.
If you need tension springs with small coil diameter and large wire diameter, please contact us.
What is a tension spring?
A tension spring, also called a coil extension spring, is a commonly used spring (see the photo). It is available in various sizes with different wire thicknesses.
When stretched, it causes repulsive force. Tension springs are widely used next to compression springs. The tension spring is used to operate with a tension load in the opposite direction of compression. The tension spring is used in various machines and apparatuses, and usually have hooks at both ends. It is available in various shapes.
Tension springs are typically made of piano (steel) wires or stainless wires, but they can also be made of special materials such as oil tempered steel wire, plated wire, phosphor bronze wire, and inconel alloy wire.
Tension springs are made using a special machine called a coiling machine onto which long wire material is set. Then they are made through low temperature annealing, shot peening, cleaning, rust-proofing, and inspection, In this way, they are manufactured by forming wire material at room temperature.
Tension springs of Sasaki-Hatsujo
Sasaki-Hatsujo excels in manufacturing small diameter coil springs out of thick wire materials.
We manufactures wire springs (coil springs) with a strict D/d (ratio of coil diameter to wire diameter) condition. Our tension springs with small D/d radio are best suitable to a narrow space.
While manufacturing tension springs, their sizes and shapes will become different than those intended due to return by residual stress through the processes such as low temperature annealing, shot peening, and presetting. Difference becomes larger in case of springs with larger wire diameters.
With its long experience, Sasaki-Hatsujo calculates the degree of change which will be caused through manufacturing processes and makes the products which meet your strict specifications.
Specifications for tension springs
Sasaki-Hatsujo manufactures tension springs of the following specification range.
| Wire diameter | 0. 1 mm to 16 mm |
|---|---|
| Extended length | 3,000 mm or more |
| D/d (ratio of coil diameter to wire diameter) |
3 or less |
| Special shaped hook | We can also fabricate special shaped hooks. |