Bayonet joint: two studs in L-slots, locked by a 30° turn — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/bayonet-joint-mechanism/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)
Basis: Xem Studio design following Brown No. 245 (1868)
Catalog version: 2026-10-20

Sizes: see table below
- Two studs on the inner tube slide straight into the two L-shaped slots of the socket; a part turn then carries them along the slots' short legs to their closed ends, where they hold the tubes together against being pulled apart. Turning back and pulling releases it.
- Ø20 tube in a Ø20 socket bore (line on line), Ø3 studs, slots 3 wide, 8 mm deep with a 30° turn; drawn locked, each stud seated in the round end of its slot.
- Brown's No. 245 (bayonet joint).
- Parts (each has its own page): bayonet-tube-20x14-studs-3, bayonet-socket-24x20-l-slots, dowel-pins-metric.
- Brown's movement No. 245 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.

parameter  value
tube  Ø20
studs  2 × Ø3
slot  8 axial + 30° turn, 3 wide
lock  30° turn

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Henry T. Brown (1868, public domain): Five Hundred and Seven Mechanical Movements — scan on archive.org — web — Publisher's page; dimensions are facts — https://archive.org/details/fivehundredseven00browiala
- 507movements.com: Brown's movement No. 245: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_245.html

Free files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/bayonet-joint-mechanism/index.json
API: https://xemstudio.com/api/geometry?object=bayonet-joint-mechanism