Extension Springs

The Extension springs (also called a pull spring) is a spiral spring that bears the axial tension. The tensile springs are usually made of circular cross section materials. In the absence of load, there is no gap between the ring and the ring of a stretch spring.

Extension springs is a spiral spring under axial tension, the hook is in the form of long side hook spring, spring hook, hook hook at British spring, spring, spring spring hook beak semicircular hook, and so on, “hook” is used to ensure the tension tension of the spring source, generally with circular cross section material made of spring steel, without load when the tension between the rings are generally tight and there is no gap, the tension spring back after the (pull), to control the mechanical movement, energy storage, measurement of the size, stretching the spring most usually in a certain degree of tension, even in the absence of any load under the condition of. This initial tension determines the tightness of a stretch spring coiling in the absence of any load.

Custom-Made Extension Springs

Extension Spring Ends

Design of Extension Springs

The following is a necessary material for a stretch spring.

(1) free length: (a) the length of the total length, (b) the length of the whole circle, and (c) in the hook circle.
(2) control diameter: (a) outer diameter, (b) inner diameter, (c) inner diameter of the casing.
(3) wire size “line diameter”.
(4) material (type, grade).
(5) the number of cycles: (a) the number of the total circle and (b) dextral or left-hand.
(6) the form of the end.
(7) the load in the hook.
(8) load rate, torsion, per inch.
(9) maximum stretch length.
The tensile spring (Extension Spring) is a typical spring, that is, the representative of spring, from straight cylinder to all kinds of variants, and even the various shapes of hooks can be designed according to design.
The tensile spring (Extension Spring) is used for the reverse application of the compression spring, and its application scope is generally less than that of the specific product category, but the operation control is higher than the compression spring.
Compression springs (Compression Spring)
Because of the ability to withstand pressure, the two ends can be open or closed or smooth or smooth. The following is the necessary data for a compression spring:
(1) control the outer diameter of the diameter (Controlling diameter) (a), the inner diameter of (b), the inner diameter of the casing of (c), and the outer diameter of the circular rod worn by (d).
(2) wire or bar size (Wire or bar size).
(3) material (type and grade).
(4) the number of cycles: (a) the number of the total circle and (b) dextral or left-hand.
(5) the form of the end (Style of ends).
(6) the load under the length of a certain torsion zone.
(7) the load ratio within the range of one inch to several inches.
(8) the maximum body height “free length” (Maximum solid height).
(9) the minimum compression height in the application.


Extension Springs are widely used in medical breathing equipment, motion control, medical mobile devices, hand tools, family care equipment, shock absorber, pump springs, mechanical and electronic protection hardware, fluid control valves, mechanical aerospace components, actuators, switchgear machines and meters. The materials are stainless steel, steel, high carbon steel, Qin, copper, oil tempered spring steel alloy etc..

Request A Quote, Please offer following information

1.Type of Material:
2.Wire Diameter:
3.Outside Diameter: and Inside Diameter:
4.Body Length: Number of Coils:
5.Overall Length:Length inside hooks:
6.End Style:
7.End Type:
8.Relationship of Ends:
11.Other information that is not required but helpful if known:

Are you looking for other types of springs

Please contact us for quotation