Direct answer: Zhengna Technology manufactures custom extension springs, also called tension springs, where hook design, initial tension, load behavior, material choice, and surface treatment must match the buyer drawing and application.
| Buyer check | Why it matters |
|---|---|
| Material and wire diameter | Controls load, fatigue life, corrosion resistance, and forming stability. |
| Load points and working range | Confirms the spring performs in the real installed condition. |
| Heat treatment or stress relief | Stabilizes force, dimensions, and fatigue behavior after forming. |
| Surface treatment | Matches corrosion, appearance, and assembly environment requirements. |
| Inspection and packaging | Protects traceability, load consistency, and deformation-free shipment. |
Hook deformation, unstable initial tension, fatigue failure, and tangling during shipment are common risks.
Specify material, wire diameter, body dimensions, hook style, initial tension, load points, finish, and quantity.
Yes. Hook style and end geometry can be made according to drawings and application requirements.
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