Note: these springs are cut from continuous lengths and I form the loops on the ends, please ask if you need hooks.
We have limited stock at the moment but will be ordering more, so if you have any requirements or questions please ask.
Tension springs are ordered by spring diameter ('width' on the image), the wire diameter and the overall length. So if you order a 30mm spring, it will be 30mm overall, including the loops.
To order lengths not listed, please order multiples adding up to the length you require - or nearest length above (i.e. 250mm = 2x100mm + 1x50mm) , the prices are per mm so there will be no extra charge doing this.Then 'contact seller' to tell me exactly what you want (i.e. one length uncut of 250mm). If no further instructions are given, all springs will be cut to the ordered lengths i.e. 2x100mm & 1x50mm.
To calculate the inside diameter, subtract 2 x the wire diameter from the outside diameter, then take off another 5% from your answer. This should give you a safe measurement.
How to calculate the Rate of a spring
The Rate given in the listings (N/mm/cm) are for a 1 cm length and are given ONLY as a guide. NOTE: The Rate is dependant on the number of active coils in the spring, so will change with the length ordered.
For the techies-
Rate is the number of Newtons applied per mm of deflection
1"=25.4mm ( Metric / Imperial conversion chart below)
1Kg=9.806N
1lb=4.448N
1Kg=2.205lb
For the less techie, 1 is very soft and 50 is very hard