Coil Spring is open helical spring that offers resistance to a compressive force applied axially. Custom 
coil springs are usually coiled as a constant diameter cylinder. Most coil springs with material diameters under three-eighths inch are cold coiled. Almost all custom coil springs using over five-eighths in. bar stock are hot coiled. There is an overlapping area from three-eighths in. to five-eighths in. material size in which the custom coil springs may be either cold coiled or hot coiled.The transportation industry is the largest user of hot coil springs. Agricultural implement manufacturers and construction equipment builders make up the next largest segment.
coil springs are usually coiled as a constant diameter cylinder. Most coil springs with material diameters under three-eighths inch are cold coiled. Almost all custom coil springs using over five-eighths in. bar stock are hot coiled. There is an overlapping area from three-eighths in. to five-eighths in. material size in which the custom coil springs may be either cold coiled or hot coiled.The transportation industry is the largest user of hot coil springs. Agricultural implement manufacturers and construction equipment builders make up the next largest segment.In Ordering Coil Springs Give The Following Information As Completely As Possible
- Free Length, Maximum, Minimum.
- Controlling Diameter, Outside Diameter Maximum. Inside Diameter Minimum. Pitch Diameter. Works Inside (Dia. Hole). Works Over (Dia. Shaft).
- Number of Coils.
- Wire Size. Decimal size if possible. Material, Kind and Grade.
- Loads at deflected positions.
- Style of Ends, (see illustrations). Right or Left Hand Wound.
- Finish. Plain unless otherwise specified.
- Maximum Solid Length.
- Frequency of Coil.
How to Determine Rate For Coil Springs
- Rate which is the change in load per unit deflection, may be determined by the following procedure:
- Deflect spring to approximately 20 percent of available deflection and measure load (P1) and spring length (L1).
- Deflect spring to approximately 80 percent of available deflection and measure load (P2) and spring length (L2). Be certain that no coils (other than closed ends) are touching L2.
- Calculate rate (R) lb./in. (N/mm)R = (P2 - P1) / (L1 - L2)