A constant force spring in type 301 stainless for roller blind mechanisms, with the grade stated explicitly. 301 work hardens to a higher spring temper than 304, which is why it is the standard material for constant force springs rather than a substitute for it.
The grade is chosen for its work hardening behaviour, which is what allows a thin strip to store and release force reliably over many cycles.
Force stays level from fully extended to fully retracted, which is what makes a blind operate smoothly.
Force and stored length are calculated from your actual blind rather than approximated from a size chart.
Keep the spring retained until it is fitted to the tube and never release a coiled constant force spring by hand. The stored energy in a blind spring is substantial and it will unroll violently.
Blinds that creep down under their own weight because the spring force is too low at full drop
Constant force springs supplied in a grade that does not hold its temper
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 | Flat 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 a 304 constant force spring, 301 holds a higher spring temper and gives more reliable long term force. Against a torsion mechanism, it gives far smoother operation across the drop.
301 work hardens further during rolling, giving the higher spring temper a constant force spring needs. 304 is the better general corrosion choice but a poorer spring.
Tell us your target cycle count and it is designed against it. Blind springs are cycled thousands of times over their life.
Within a band. Tell us the range and we will say where it must be split into two specifications.
Send your drawing, dimensions or a sample. We will confirm the specification and come back with a price and a lead time.
