Helical Coil Spring 1.Excellent surface.easy for installation 2.ROHS standard 3.made of high quality wire 4.flexible in cust Helical Coil Spring 1.Steel wire diameter from 0.5mm to 20mm2.Compression and No deformation 3.Good elasticity4.Applications: Automotive, medical device, electronics, toy etc.5.Surface treatment:Zinc,Nickel,silver,golden,tin,powder coating. Helical Coil Spring