The compression spring is a helical spring with permanent clearance between active coils capable of carrying the outer opposing forces actuating in its axis.
 
Dimensions
| d | wire diameter [mm, in] | 
| D | mean spring diameter [mm, in] | 
| D 1 | outside spring diameter [mm, in] | 
| D 2 | inside spring diameter [mm, in] | 
| H | working deflection [mm, in] | 
| t | pitch of active coils in free state [mm, in] | 
| a | space between active coils in free state [mm, in] | 
| s x | spring deflection [mm, in] | 
| L x | spring length [mm, in] | 
| F x | working force exerted by the spring [N, lb] | 
| W 8 | deformation energy [J, ft lb] | 
| x | index responding with the spring state | 
Coiling
States