Spring Terminology

Those active coils which are free to deflect under load.

Spring using the elasticity of air, which is one of the fluid springs.

The relative position of the plane of the hooks or loops of extension springs to each other.

A round, hardened rod or shaft upon which springs are wound., Also called a “mandrel”

Heating of electroplates springs to relieve hydrogen embrittlement.

A thin blue film of oxide on ferrous alloys, sometimes used to indicate that the material has been stress relieved.

Bowing or lateral deflection of compression springs when compressed, related to the slenderness ratio (L/D)

Eccentric retaining ring shaped like leter “C”, including two types: for one-shaft-use and for in-bore-use.

Concentric retaining ring shaped like leter “C”, including two types: for one-shaft-use and for in-bore-use.

Spring made of ceramics (sintered materials mainly comprising aluminum oxide and the like) as called by its material.

Generic term for circular springs, such as C-type retaining ring.

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

Spring formed in low temperature, such as the cold formed coil compression spring and the cold formed coil extension spring as called by its forming method.

Combination of Multiple springs to obtain the required characteristics. (Springs may be combined in a serial or parallel way. A combination spring comprising two springs is called serial double spring or parallel double spring.)

Spring made of composite rresin materials, as called by its material.

Spring subjected mainly to a compressive force, in the narrow sense, helical compression spring.

Spring that indicates constant load or torque despite of the deflection change.

Spring deflection of which is linear to the load applied.

Motion of spring ends or arms under the application or removal of an external load (P)

Retaining ring shaped like letter “E” for on-shaft-use.

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.

Spring subjected mainly to an extensive force, in the narrow sense, helical extension spring (tension spring).

Various shapes of spring for fastening.

Various shapes of spring made of thin flat materials, as called by its material.

Spring using the elasticity of gas or liquid, as called by its material.

Various shapes of springs made of wire, as called by its material.

Angle between the arms of a torsion spring when the spring is not loaded

The overall length of a spring in the unloaded position.

The lowest inherent rate of free vibration of a spring itself (usually in cycles per second) with ends restrained.

Spring using the elasticity of inert gas such as Argon or Helium, which is one of the fluid springs.

Spring using the elasticity of inert gas such as Argon or Helium, which is one of the fluid springs.

See Rate (R)

Retaining ring used for shafts without grooves.

Fixturing a spring at elevated temperature to minimize loss of load at operating temperature.

The spiral form (open or closed) of compression, extension, and torsion springs.

Open loops or ends of extension springs.

Spring formed in low temperature, such as the cold formed coil compression spring and the cold formed coil extension spring, as called by its forming method.

In the spring and wire industry, heat pressing is a process used to shape or set the form of springs and wire components by applying heat and pressure, enhancing their strength and stability.

Hydrogen absorbed in electroplating or pickling of carbon steels, tending to make the spring material brittle and susceptible to cracking and failure, particularly under sustained loads.

Spring using the elasticity of gas or liquid, as called by its material.

The mechanical energy loss that always occurs under cyclic loading and unloading of a spring, proportional to the area between the loading and unloading load-deflection curves within the elastic range of a spring.

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 caused a deflection (F).

Generic term for washers for locking using the spring action.

Coil-like wire shapes at the ends of extension springs that provide for attachment and force application.

Spring using the repulsion force and attraction force by magnetism, as called by its type of function.

Outside spring diameter (O.D.) minus one wire diameter (d)

Spring made of metallic materials as called by its material.

Coefficient of stiffness for extension and compression springs.

Coefficient of stiffness used for torsion and flat springs (Young’s Modulus).

In the spring industry, Moment (M) refers to the measure of the rotational force or torque applied to a spring, typically in torsion springs.

Spring made of nonferrous metal, as called by its material.

Spring the deflection of which is not linear to the load applied.

Spring made of non-metallic materials as called by its material.

End of a 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.

Spring using the elasticity of air, which is one of the fluid springs.

The process of intentionally compressing a spring to its solid height (where all coils touch) to induce a beneficial set or permanent deformation.

Spring the deflection of which is not linear to the load applied.

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.

Stresses induced by set removal, shot peening, cold working, forming or other means. These stresses may or may not be beneficial, depending on the application.

Circular spring for preventing the axial movement by snapping into the groove formed on the shaft or the hole. (A grip ring is used for grooveless shafts.)

Spring using the elasticity of rubbers, as called by its material.

Permanent distortion which occurs when a spring is stressed beyond the elastic limit of the material.

Ratio of spring length (L) to mean coil diameter (D).

Circular spring for preventing the axial movement by snapping into the groove formed on the shaft or the hole. (A grip ring is used for grooveless shafts.)

Length of a compression spring when under sufficient load to bring all coils into contact with adjacent coils.

A spring is a mechanical device that stores and releases energy by resisting deformation, often used to absorb shock or apply force.

Ratio of mean coil diameter (D) to wire diameter (d).

Generic term for washers for locking using the spring action.

See Closed and ground ends.

The ends of a compression spring where the last coil is flattened and closed to be perpendicular to the spring’s axis.

Spring made of steel materials as called by its material.

The difference in operating stresses at minimum and maximum loads.

To subject springs to low-temperature heat treatment so as to relieve residual stresses.

Shot peening is a surface treatment process where small spherical media are blasted onto a material to improve its strength and fatigue resistance.

Angular deviation between the axis of a compression spring and a normal to the plane of the ends.

As in Squareness of ends, except with the spring under load.

A twisting action in torsion springs which tends to produce rotation, equal to the load multiplied by the distance (or moment arm) from the load to the axis of the spring body. Usually expressed in inch-oz., inch-pounds or in foot-pounds.

Twisting Spring subjected mainly to a twisting moment, in the narrow, sense, helical torsion spring. (torsion)

Number of active coils (n) plus the coils forming the ends.

Spring the deflection of which is not linear to the load applied.

Spring washer made by turning wire and formed into a waved shape.

Spring washer made of thin ring plate on which waving is formed. (curved washer)

Various shapes of springs made of wire, as called by its material.

Coil spring made of wire.