The extension spring is generally intended to operate by extension and is therefore the opposite of the compression spring.
This is calculated as a compression spring possibly taking a prestressing force into account called initial tension. Extension springs are generally cylindrical in shape and can be differentiated by the variety of hooks that can be formed at their ends. (English hooks, German hooks, elongated hooks, etc.).
Available in all dimensions and qualities from 0.1 to 8 mm in wire thickness in small, medium or large series. Extension springs are available up to 20 mm in small and medium series only.
SM, SH, DH grade spring steel, …
Pre-coated galvanised SM grade, galvanised SH grade, Bezinal © SM grade and Bezinal © SH grade steel
Oteva © silicon-chrome oil-tempered steel
Stainless steel 1.4310, 1.4310 HS, 1.4401, 1.4568, 1.4462, 17/7 PH
Low-carbon stainless steel 1.4301
1.4441 implant grade stainless steel
Inconel 600, 625, 718, 750
Monel, Nimonic, Elgiloy …