Torsion spring wire Ø0.8, OD 8, 6 coils — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/torsion-spring/  (CC BY 4.0)
Basis: Close-wound helical torsion spring with two straight tangential legs; rate E d⁴ / (3667 D n) N·mm per degree
Catalog version: 2026-10-20

Sizes: see table below
- Six close-wound coils of 0.8 wire, OD 8, ID 6.4, with two straight legs reaching 10 mm from the coil axis. Envelope 14 × 8 × 5.7.
- Torsion rate in N·mm per degree = E d⁴ / (3667 D n), E the wire's elastic modulus, D the mean Ø (7.2), n the coils.
- The ID (6.4) goes over an arbor; the legs bear on the two parts it sets against each other, such as a pawl and its frame.

feature  value_mm
wire Ø  0.8
OD / ID  8 / 6.4
coils  6
leg reach from axis  10
envelope  14 × 8 × 5.7

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, 1 parts): https://xemstudio.com/files/hardware/torsion-spring/index.json
API: https://xemstudio.com/api/geometry?object=torsion-spring