Glossary of Spring Terminology
There are many technical terms used when discussing springs. Here are some of the most common terms in use and what they mean.
If you have any more questions, please feel free to give us a call.
Those coils which are free to deflect under load
the relative position of the plane of the hooks or loops of extension springs to each other
heating of electroplated springs to relieve hydrogen embrittlement
Ends of compression springs where pitch of the end coils is reduced so that the end coils touch
As with closed ends except that the end is ground to provide a flat plane
See Solid Height
Coiled with adjacent coils touching
See Pitch
Motion of spring ends or arms under the application or removal of an external load
Maximum stress to which a material may be subjected without permanent set
Maximum stress at which any given material will operate indefinitely without failure for a given minimum stress
Angle between the arms of a torsion spring when the spring is not loaded
The overall length of a spring in the unloaded position
See Rate
Fixturing a spring at the elevated temperature to minimize loss of load at operating temperature
The spiral form (open or closed) of compression, extension and torsion springs
"Open Ends, Not Ground” followed by an end grinding operation
See Heat Setting
The force that tends to keep the coils of an extension spring closed and which must be overcome before the coils start to open
The force applied to a spring that causes deflection
Coil like wire shapes at the ends of extension springs that provide for attachment and force application
Outside spring diameter (O.D.) minus one wire diameter (D)
End of compression spring with a constant pitch for each coil
“Open Ends, Not Ground” followed by an end grinding operation
Acid treatment of stainless steel to remove contaminants and improve corrosion resistance
A material that is deflected so far that its elastic properties have been exceeded and it does not return to its original condition upon release of load is said to have taken a “permanent set”
The distance from center to center of the wire in adjacent active coils (recommended practice is to specify number of active coils rather than pitch)
Change in load per unit deflection, generally given in pounds per inch
The process of closing to solid height a compression spring which has been coiled longer than the desired finished length, so as to increase the apparent elastic limit
Permanent distortion which occurs when a spring is stressed beyond the elastic limit of the material
Length of a compression spring when under sufficient load to bring all coils into contact with adjacent coils
Ratio of mean coil diameter (D) to wire diameter
Refer to closed and ground ends
Refer to closed ends
To subject springs to low temperature heat treatment so as to relieve residual stresses
A cold-working process in which the material surface is peened to induce compressive stresses and thereby improve fatigue life
Angular deviation between the axis of a compression spring and a normal to the plane of the ends
Number of active coils (n) plus the coils forming the ends
