Engineering lab · Interactive tool

Compression Spring Calculator.

Estimate rate, force, corrected shear stress, solid height, and coil-bind margin for a round-wire helical compression spring.

Round-wire compression spring / static screening

Live calculation

01Spring geometry

02Material limits

Helical compression springA helical compression spring between two loading plates.FREE LENGTHAXIAL LOAD
Helical spring rate + Wahl correctionk = Gd⁴ / 8D³Nₐ

Spring results updated. Spring rate 6.05 newtons per millimeter. Force 72.6 newtons. Coil-bind margin 23 millimeters.

Spring rate6.05 N/mmindex C = 8
Force at deflection72.6 N12 mm travel
Corrected shear280.19 MPaWahl factor 1.184
Coil-bind margin23 mmFoS 2.5
Revision1.2
AuthorJared Maffucci
Last technical review23 July 2026
Input guardrailsFinite values; nonnegative magnitudes; physical geometry and material domains enforced
UsePreliminary engineering judgment only
Variable definitions
  • d: wire diameter
  • D: mean coil diameter
  • Nₐ: active coils
  • G: shear modulus
  • δ: deflection
Hand-verified examples
  • 2 mm wire reference: 4.8401 N/mm and 20 mm margin
  • Invalid coil geometry: input is rejected
Change log · revision 1.2

Added visible variables, two verification examples, and an experience connection. Calculation method is unchanged.

Related engineering capability

A viable rate still needs a viable spring

The model applies the classical helical-spring rate and Wahl curvature correction. It helps expose geometry, load, stress, and travel tradeoffs early.

Production design must also resolve fatigue, end conditions, free-length variation, set, buckling, surge, relaxation, corrosion, temperature, and supplier process capability.

Before specifying the spring

  • Define force targets at every operating position
  • Preserve practical clearance before solid height
  • Check spring index and manufacturability
  • Evaluate fatigue at mean and alternating stress
  • Control buckling, guidance, ends, set, and relaxation

Direct conversation

Review the product, the available evidence, and the decision blocking progress.

Send a concise, non-confidential brief. You will work directly with Jared from the first review through final handoff.

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