Elementary helical spring screen

Compression spring rate

Inputs

Wire diameterdRound-wire diameter for the close-coiled spring model.

Mean coil diameterDCenterline coil diameter, not outer or inner diameter.

Active coilsNacoilsNumber of coils participating in elastic deflection.

Shear modulusGUser-entered material shear modulus at the stated condition.

Applied deflectionδStated compression from the free configuration.

Elementary spring rateMRR

9.6436

N/mm

Ideal spring forceF

115.72

Spring index D/d

—

Uncorrected wire torsional shearτ

147.34

k = Gd⁴/(8D³Na); F = kδ; τbasic = 8FD/(πd³)

A first-pass number, not a code check, certification, or approval. Read the method and its limits below. What this is and is not.

Calculation snapshot

Formula version 1.0.0

Elementary spring rate	9.6436 N/mm
Ideal spring force	115.72 N
Spring index D/d	8 —
Uncorrected wire torsional shear	147.34 MPa

k = Gd⁴/(8D³Na) · F = kδ · τbasic = 8FD/(πd³)

Acxess compression-spring rate reference: https://www.acxesspring.com/compression-spring-rate.html

This printout is a record of displayed inputs and deterministic formula output. It is not an approval, certification, or engineering conclusion.

Method

Calculate elementary linear spring rate, force at a deflection, spring index, and uncorrected torsional shear from coil geometry and shear modulus.

k = Gd⁴/(8D³Na); F = kδ; τbasic = 8FD/(πd³)

When

Don’t

This is an elementary close-coiled round-wire spring screen. It excludes Wahl/direct-shear correction, end condition, solid height, buckling, coil clash, residual stress, material allowables, fatigue, relaxation, corrosion, temperature, dynamics, and spring selection.