PARAMETRIC · 3D · STEP / STL / 3MF
Coil SpringCOMPRESSION SPRING
Enter wire diameter, outer diameter, turns and pitch, choose open, closed or ground ends, and get a helical compression spring with its spring rate — download STEP, STL or 3MF.
- EndsOpen / closed / ground
- CalcSpring rate k
- OutputSTEP · STL · 3MF · DXF
LIVE · COMPRESSION SPRING
d1.5 · OD15 · n8
SCALE 1:1 · mm
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CALCULATED · SPEC
AUTO-COMPUTED
D
13.50mm
Mean diameter
Di
12.00mm
Inner diameter
C
9.00
Spring index C = D/d
L0
36.50mm
Free length
Ls
16.50mm
Solid height
Nt
10.0
Total coils
k
2.550N/mm
Spring rate (steel)
δ
20.00mm
Max deflection
HOW-TO
How to generate a coil spring STEP / STL file
- 1Enter wire diameter, outer diameter, active coils and pitch.
- 2Pick the end type and grinding; read the spring rate and free length on the spec cards.
- 3Check the spec cards and any warnings.
- 4Download STEP, STL or 3MF — or send it to Orinovate for a quote.
What is a helical compression spring?
Wire coiled into a helix that resists compression — used in buttons, valves, clamps and return mechanisms. Key parameters are wire diameter d, mean diameter D, active coils n and pitch p; a spring index C = D / d of 4–16 is practical.
Key formulas
Spring rate k = G·d⁴ / (8·D³·n). Free length: open ends L0 = n·p + d; closed ends (one dead coil each end) L0 ≈ n·p + 3d. Solid height Ls = (total coils + 1)·d, minus d when ground. The spec card uses G = 79.3 GPa for spring steel and ignores the Wahl stress correction.
Specs at default parameters
| Parameter | Value | Range |
|---|---|---|
| Wire diameter (d) | 1.5 mm | 0.2–20 |
| Outer diameter (OD) | 15 mm | 1–300 |
| Active coils (n) | 8 | 1–50 |
| Pitch (p) | 4 mm | 0.3–100 |
| End type | Closed | Open / Closed |
| Ground ends | Not ground | Not ground / Ground |
| Mean diameter (D) | 13.50 mm | — |
| Inner diameter (Di) | 12.00 mm | — |
| Spring index C = D/d (C) | 9.00 | — |
| Free length (L0) | 36.50 mm | — |
| Solid height (Ls) | 16.50 mm | — |
| Total coils (Nt) | 10.0 | — |
| Spring rate (steel) (k) | 2.550 N/mm | — |
| Max deflection (δ) | 20.00 mm | — |
FAQ
How is the spring rate calculated?
k = G·d⁴ / (8·D³·n), with G the shear modulus (spring steel 79.3 GPa = 79300 N/mm², stainless ≈ 68.5 GPa), d the wire, D the mean diameter and n the active coils. For d = 1.5, D = 13.5, n = 8: k ≈ 2.5 N/mm.
Do 3D-printed springs work?
PLA springs creep and snap — fine for display or very light loads. PETG, nylon and TPU last longer. For real loads use a metal spring; this model serves design, assemblies and as a reference for ordering one.
Closed vs ground ends?
Closed ends have one dead coil touching at each end so the spring stands. Ground ends are additionally ground flat for square loading and less buckling; grinding shortens the free length by about one wire diameter.
Which software opens the coil spring STEP file?
STEP (AP214) opens in Fusion 360, SolidWorks, FreeCAD, Onshape and Rhino. STL / 3MF import directly into Bambu Studio, PrusaSlicer or Cura.
Is it free?
Yes — no sign-up, no fees. Need a physical part? Send it to Orinovate for an instant quote in FDM, SLA, SLS, MJF or CNC.
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Need a physical part?
Send the model straight to Orinovate's instant quote: FDM, SLA, SLS, MJF, metal printing and CNC, made in Hsinchu, Taiwan.
About STEP / STL / 3MF / DXF
- STEP (.step / .stp, AP214) keeps exact dimensions and surfaces for editing in Fusion 360, SolidWorks or FreeCAD.
- STL and 3MF are triangle meshes that import directly into Bambu Studio, PrusaSlicer or Cura.
- DXF is the top-view 2D outline, ready for laser cutting, waterjet or CNC routing.
- All models are in millimetres at true scale.