Spring Glossary

• End Configurations: The design of the spring's ends, including hooks, loops, or other configurations.
• Free Length: This represents the spring's length when it's not under any load or tension, indicating its relaxed or uncompressed state. Free length determines the available range of motion or deflection for the spring.
• Hole Diameter: The hole diameter is the space where a spring is inserted. It should be larger than the spring's outside diameter to account for tolerance and spring expansion under load.
• Initial Tension: Initial tension is the preload applied to the extension spring when it's in its free, unloaded state. It's specified to ensure the spring remains taut when attached to the application. Initial tension is influenced by the wire diameter and coil count.
• Inner Diameter: The inner diameter refers to the space inside the coil, which can vary based on the application's requirements. It influences initial tension and how the spring fits over a shaft or rod.
• Load at Solid Height: This measures the force required to fully compress a compression spring until its coils are pressed together. It helps ensure that the spring can handle an assembly's maximum operating load, preventing it from bottoming out.
• Load or Force Requirements: The amount of force the spring needs to exert or withstand.
• Material Selection: The choice of spring material based on application requirements.
• Maximum Deflection: This indicates the distance the spring can stretch from its free length under the application's maximum load. Designing for sufficient deflection without exceeding the spring's elastic limit is crucial.
• Outer Diameter: The overall diameter of the spring coil. It affects the spring's size and fit within the application.
• Pitch: The pitch is the spacing between successive coils and is determined by dividing the free length by the total coil count. It impacts the spring's flexibility and rate.
• Rate: Spring rate measures the change in load per unit deflection (in pounds per inch or Newtons per millimeter).
• Rod Diameter: This measurement pertains to the rod inside a spring, serving as a guide shaft to prevent spring buckling under load. The rod diameter should be smaller than the spring's inside diameter, factoring in tolerance.
• Solid Height: Solid height is the length of a spring when fully compressed, with all coils pressed together.
• Spring Rate: Also known as stiffness or rate constant, the spring rate represents the force exerted per unit of deflection (typically measured in pounds per inch or Newtons per millimeter). It's calculated as the change in force divided by the change in length and influences how the spring reacts to load variations.
• Spring Set: Spring set is the permanent deformation that occurs when a spring is loaded beyond its material's elastic strength. It may be desirable or undesirable depending on the application.
• Stress: The spring's dimensions, along with the load and deflection requirements, determine the stresses within the spring. Stress and stress range affect the spring's lifespan.
• Total Coils: The total number of coils affects the spring rate and its deflection capabilities. Increasing the number of coils generally results in a softer, more flexible spring.
• Wire Diameter: This is the size measurement of the raw material used to create the spring. This parameter represents the spring wire's thickness, significantly impacting the spring's strength, flexibility, and load-bearing capacity. Choosing the appropriate wire diameter is essential to meet desired spring force and deflection characteristics.