Compression springs, wire Ø0.5–1.6, OD 6–16 — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/compression-springs/  (CC BY 4.0)
Basis: Helical compression spring with closed ends; rate k = G d⁴ / (8 D³ n), D = OD − d
Catalog version: 2026-10-20

Sizes: see table below
- Envelopes at exact wire Ø, OD, ID (OD − 2 × wire) and free length, with closed (flat-ring) ends.
- Rate k = G d⁴ / (8 D³ n): G the shear modulus of the wire, d the wire Ø, D the mean coil Ø (OD − d), n the active coils. Halving the coils doubles the rate.
- Spring index D/d between 4 and 12 is makeable, 6–9 comfortable; these are 9 except the 0.5 × 6 at 11.
- Solid height is about (n + 2) × d; usable deflection about 0.8 × (free length − solid height). A pocket for one is drawn at the OD and a guide rod at the ID (see Mating features).

file  wire Ø  OD  ID  free length  coils  index D/d
compression-d0.5-od6-l20  0.5  6  5.0  20  8  11.0
compression-d0.8-od8-l25  0.8  8  6.4  25  10  9.0
compression-d1-od10-l30  1.0  10  8.0  30  10  9.0
compression-d1.2-od12-l40  1.2  12  9.6  40  12  9.0
compression-d1.6-od16-l50  1.6  16  12.8  50  10  9.0

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Wikipedia: Spring (device) — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Spring_(device)
- McMaster-Carr: Compression springs (free STEP per part, for your own design use; no redistribution) — STEP, PDF — McMaster-Carr site terms [verify license at link] — https://www.mcmaster.com/products/compression-springs/
- Lee Spring: Spring design formulas — web — Lee Spring site [verify license at link] — https://www.leespring.com/learn-about-springs
- Long Earth Society: Engine and rig builds — web, video — LES site — https://longearthsociety.com/engineering/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 5 parts): https://xemstudio.com/files/hardware/compression-springs/index.json
API: https://xemstudio.com/api/geometry?object=compression-springs