... can produce a variety of tension spring according customers' sample. 2.Wire Dia:0.1mm-10mm. 3.High quality and low price ... closed coil design and hooked ends. MaterialPiano wire, stainless steel, High Carbon Steel, Nickel Plated, Phosphor copper Bronze, Copper Bronze, Beryllium ... and then send you a print out for your approval. Tension spring can available in many fields,Auto ,industry,etc. 1 ...