Glossary of terms

  • Active Coils (n) - The coils which are free to deflect under a force.
  • Alloy - A metal composed of two or more metal elements bound together.
  • Arbor - A round rod on a spring coiler over which wire is coiled to form a spring.
  • ASTM - The American Society for Testing Materials.
  • Baking - Heating electroplated springs to remove hydrogen.
  • Brass - A copper-base alloy of copper and zinc.
  • Bronze - A copper-base alloy of copper and tin.
  • Buckling - Lateral deflection movement of a compressed spring and is related to the slenderness ratio.
  • Deflection (F) - Displacement of the ends or arms of a spring on the application of an external force (P).
  • Elastic Limit - Maximum stress which a spring can be stressed without taking a permanent set.
  • Endurance Limit - Maximum stress which can be repeatedly applied without incurring spring failure.
  • Fatigue Failure - When a spring is deflected continually, the metal becomes fatigued and failure may occur at a stress level far below the elastic limit.
  • Fatigue Life - Number of deflection cycles until a failure occurs at a predetermined stress.
  • Fatigue Strength - Stress at which failure occurs after a specific number of deflections.
  • Force (P) - Active power applied to a spring to cause deflection. Is erroneously called load.
  • Free Angle - Angle between the arms of a torsion spring when the spring is not loaded.
  • Free Length - The overall length of a spring in the unloaded position.
  • Frequency (Natural) - The number of cycles per minute at which a spring will vibrate freely once it has been excited.
  • Gauge - A standard for measuring material thickness.
  • Gradient (Rate) (R) - Change in force per incremental unit of deflection.
  • Heat Setting - Deflecting a spring in a fixture at elevated temperatures in order to reduce loss of load at operating temperature.
  • Helical - Springs of spiral or cylindrical shape such as compression, extension, or torsion springs.
  • Hysteresis - The difference in forces at various deflection when loading and unloading a spring.
  • Initial Tension (Pi) - A force wound directly into an extension spring during coiling to hold the coils together.
  • Load (Force) (P) - Active power applied to a spring to cause a deflection (F).
  • Modules in Shear or Torsion (G) - Coefficient of stiffness for extension and compression springs.
  • Modules in Tension or Bending - Coefficient of stiffness for torsion and flat springs.
  • Passivating - An acid dipping treatment applied to stainless steel to remove contaminants and improve corrosion resistance.
  • Permanent Set - The difference in length of a highly stressed spring upon release of a force.
  • Pitch (p) - The distance from the center of the wire in two adjacent coils.
  • Preset - The process of closing to solid height a compression spring which has been coiled longer than the desired finish length, so as to increase the apparent elastic limit.
  • Proportional Unit - Maximum load at which starin or deformation is directly proportional to stress, at zero percent offset.
  • Rate (R) (Gradient) - Change in force per incremental unit of deflection.
  • Residual Stress - Stresses incorporated within a spring by coiling, compressing to remove set, shotpeening, cold working or induced by heat treatment.
  • Resilience - Elastic ability of a material to rebound to its original shape after deflection.
  • Set - Permanent distortion which occurs when a spring is stressed beyond the materials elastic limit.
  • Slenderness Ratio - Ratio of spring free length (L) to the mean coil diameter (D). If the ratio is over 4.0, compression springs may buckle depending on the amount of deflection.
  • Solid Height (H) - Length of compression spring when force causes coil contact with all adjacent coils.
  • Spring Index - Ratio of mean coil diameter (D) to wire diameter (d). Best ratio is between 7-13.
  • Strain - The deformation produced by a stress as compared to the original shape.
  • Stress - The force divided by the area over which it acts.
  • Stress Relieve - Low temperature heat treatment to relieve residual stresses induced during coiling.
  • Tensile Strength - Maximum force which a material is capable of sustaining. It equals force reached divided by original cross-sectional area.
  • Torque (Movement) - A twisting force in torsion springs which tends to produce rotation, equal to the force multiplied by the distance from the force to the axis of the spring body.
  • Total Coils (N) - Number of active coils (n). For compression springs add to (n) the number of dead coils forming the ends.
  • Yield Point - Stress point which will cause an elongation to the original length of the spring.

About Us

Our Process

Special Fun

Our Products

With our spring kits you can now create your own springs anytime anywhere you need to. Break a spring while on the job? No problem, just create another one. Visit our Store