engineering

Helical Spring Design Calculator

Calculate spring rate, deflection, and shear stress with Wahl correction factor for helical compression springs

Helical Spring Design Calculator

Calculate spring rate, deflection, and corrected shear stress for helical compression springs.

Formulas

k = G·d⁴ / (8·D³·N)
C = D/d   (spring index)
K_w = (4C−1)/(4C−4) + 0.615/C   (Wahl factor)
τ = K_w · 8·F·D / (π·d³)

Steel: 79 GPa | Bronze: 41 GPa

Spring Parameters

Spring Index C = D/d

8.333

Wahl Factor K_w

1.1761

Spring Rate k

10238.40 N/m

= 10.2384 kN/m

Deflection δ = F/k

48.836 mm

Corrected Shear Stress τ

346.63 MPa

Uncorrected τ (K_w=1)

294.73 MPa

Free Length Recommendation

Coil pitch (at rest): typically p ≈ 2.5·d to 4·d
Free length ≈ (N+1.5)·p for ground ends
Slenderness ratio L_f/D ≤ 4 to avoid buckling

Design Guidance

Spring index C = 4–12 (preferred range)
τ_allow ≈ 0.45·S_ut (static) | 0.35·S_ut (dynamic)
Steel wire S_ut ≈ 1500–2000 MPa (depends on d)

How to Use This Calculator

1

Enter your input values

Fill in all required input fields for the Helical Spring Design Calculator. Most fields include unit selectors so you can work in your preferred unit system.

2

Review your inputs

Double-check that all values are correct and that you have selected the right units for each field. Incorrect units are the most common source of calculation errors.

3

Read the results

The Helical Spring Design Calculator instantly computes the output and displays results with units. All calculations happen in your browser — no loading time and no data sent to a server.

Formula Reference

Helical Spring Design Calculator Formula

See calculator inputs for the governing equation

Variables: All variables and their units are labeled in the calculator interface above.

When to Use This Calculator

  • •Use the Helical Spring Design Calculator when solving homework or exam problems that require quick numerical verification of your hand calculations.
  • •Use it during the design phase to rapidly iterate on parameters before running detailed finite element simulations.
  • •Use it when reviewing a colleague's calculation or checking a vendor's data sheet for plausibility.
  • •Use it to generate reference data for a technical report or presentation without manual computation.

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