Spring Engineering and Design

Conical Helical Compression Spring Design Equations and Calculator.

This is a helical spring in which the coils progressively change in diameter to give increasing stiffness with increasing load. It has the advantage that the compressed height is small.

Where:

Stiffness:

Where:

Conical helical spring Symbols used:
W = Load (N),
s = Stiffness (N/mm)
G = Shear Modulus (Torsional) of Elasticity (N/m² or Pa),
τ = Allowable shear stress (Pa),
D₁ = smaller diameter (mm),
D₂ = larger diameter (mm),
d = wire diameter (mm),
n = number of active coils,
y = Deflection (mm),
C = Coil ratio,
K = Wahl factor,

Reference:

Mechanical Engineers Databook, Carvil