Bounded preliminary mechanics
Compression Spring Preliminary Calculator
For a close-coiled, round-wire, cylindrical cold-formed spring with linear axial response. Calculate rate, deflection at a supplied load and an estimated Wahl-corrected shear stress—not a safe maximum load.
Preliminary linear result
The equations are a close-coiled linear-elastic approximation. A NASA technical report documents the Wahl-corrected compression-spring stress form. DIN EN 13906-1:2013 is the current European calculation/design standard for linear cylindrical helical compression springs made from constant-diameter round wire/bar; its cold-formed scope includes d≤20 mm, n≥2 and spring index 4–20.
ISO 22705-1:2021 specifies measurement and test methods for general characteristics of cold-formed round-wire cylindrical compression springs and excludes dynamic testing. It is not a source for claiming this simplified calculator is an ISO design.
Required engineering checks outside this calculator: material/product standard and certificate, strength and safety factor, static or dynamic duty and cycle count, fatigue and shot peening, temperature and relaxation, tolerances, end form, actual solid height/clash allowance, free length and buckling/guidance, natural frequency/surge, corrosion and validation test.
