Heavy-duty & large extension springs up to 20 mm wire — engineered for high pulling force in industrial machinery and equipment.
GL Springs manufactures custom heavy-duty extension springs and large extension springs (large tension springs) for applications that demand strong, repeatable pulling force over long travel. Built to your load, extended length, and hook configuration in high-tensile alloy, carbon, or stainless steel — IATF 16949 certified, with samples available before mass production.
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| Wire diameter | Large gauge, up to 20 mm |
| Outer diameter | Customizable to your design |
| Free / extended length | Long bodies to your drawing |
| Hook / end type | Heavy-duty hooks, loops, threaded ends, custom |
| Materials | High-tensile / alloy steel (60Si2Mn, 55CrSi, 50CrV), carbon (65Mn), stainless (304 / 316) |
| Surface finish | Powder coating, zinc plating, hot-dip, electrophoresis for corrosion resistance |
| Standards | IATF 16949, customer drawing |
How large an extension spring can you make?
We produce large extension springs with wire diameters up to 20 mm and long free lengths for high-load industrial applications. Send your dimensions and we'll confirm feasibility.
What's the difference between a heavy-duty and a large extension spring?
"Heavy-duty" refers to high load capacity (heavy-gauge wire, high-tensile material); "large" refers to physical size. We build both — and springs that are both large and heavy-duty.
Do you provide samples?
Yes — custom samples are available before mass production (typically 5–7 business days).
Send us your load, extended length, and hook requirement — or a drawing or sample. Our engineers will recommend the optimal design and provide a fast quote.
Part of our full range of custom extension springs.
