Crank and wrist pins Ø3 × 12, 16, 19, 20 and 23 — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/pins-3mm/  (CC BY 4.0)
Basis: Solid Ø3 pins at the Ø3 pin holes of the crank discs, webs, clevises and pistons
Catalog version: 2026-10-20

Sizes: see table below
- Solid Ø3 pins, 12, 16, 19, 20 and 23 long, 0.3 chamfers both ends.
- They sit fixed in the crank disc and web pin holes, the yoke and the clevis tines, and the con-rods turn on them; each fit is listed under Mating features.
- Ø3 × 16 is the wrist pin through the free-piston plug legs; Ø3 × 23 is the alpha V-twin crank pin (disc 6, two rods and two 1 mm spacers, then a full 5 mm collar) and the Ross yoke's rocking pin.

file  Ø  length
pin-3x12  3  12
pin-3x16  3  16
pin-3x19  3  19
pin-3x20  3  20
pin-3x23  3  23

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Long Earth Society: Engine 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/pins-3mm/index.json
API: https://xemstudio.com/api/geometry?object=pins-3mm