A long bodied double hook extension spring with a black plated finish, combining a soft rate over a long stroke with a finish that suits dark equipment. It is the long travel member of our black plated extension family.
The extended body lets the spring travel a long way before the force becomes significant, which suits take-up and return duties.
Matches the 2 mm and 3 mm black plated springs so a machine using several sizes looks consistent.
Identical hooks remove orientation from the assembly step.
Ship and store long springs supported along their length. A permanent bend in the body makes the spring extend unevenly and rub against its housing.
Short springs reaching full extension before the mechanism completes its travel
Mixed finishes across the springs on one machine
Dimensional and load figures are set per order against your drawing or sample, so they are marked TBC rather than filled with catalogue numbers.
| Product Type | Tension Springs |
|---|---|
| Raw Material Options | Stainless steel, Spring steel, Carbon steel, 65Mn, Music wire |
| Wire Diameter Range | 0.1-8 mm |
| Surface Treatment Options | Zinc plating, Nickel plating, Silver plating, Gold plating, Tin plating, Galvanizing in various colours, Dacromet, Black oxide, Phosphating |
| Standard | ISO, non-standard and OEM drawings |
| Processing Route | Material sourcing → Coiling and forming → Heat treatment → Surface treatment → Quality inspection → Packing → Shipping |
| Inspection Equipment | Grinding and shot peening machinery; Precision tensile strength testers; Magnetic powder flaw detectors |
| Packing | Plastic bags, cartons or pallets, or packing to your own specification |
| Payment Terms | L/C, T/T, D/A, D/P, Western Union, 30% deposit before production, 70% balance before shipment |
| Lead Time | 7-15 days after the order is confirmed |
| Minimum Order Quantity | Quoted per part — tell us your requirement (TBC) |
| Dimensions and Load Rating | Made to your drawing or sample (TBC per part) |
Every batch follows the same seven step route, with tensile testing and magnetic powder flaw detection carried out before packing.
Available in Stainless steel, Spring steel, Carbon steel, 65Mn, Music wire, in wire from 0.1-8 mm, with any of our nine surface finishing routes. Geometry, end treatment and finish are all specified per order.
ISO 9001, SGS certificate and RoHS report (stated on the legacy site, certificates pending re-confirmation). Certificate copies are sent on request once re-confirmed.
Against the standard length 2 mm and 3 mm black plated springs, this version trades peak force for stroke. Choose it when travel rather than force is the constraint.
Tell us the installed length and wire size and we will confirm what can be coiled and shipped without distortion.
At the same wire and coil diameter, yes, at a given extension. More active coils share the deflection, which is exactly why long springs are used for long travel.
Yes. The same geometry is available in zinc, galvanised, nickel or stainless.
Send your drawing, dimensions or a sample. We will confirm the specification and come back with a price and a lead time.
