Xem Studiomeasured geometry

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Bayonet joint: two studs in L-slots, locked by a 30° turn

How does a bayonet joint lock? · Hardware · basis: Xem Studio design following Brown No. 245 (1868)

Also called: bayonet joint, bayonet mount, bayonet coupling, twist lock, unión de bayoneta, Bajonettverschluss

Exact dimensions. True size, with no printing tolerance added.

sizes
4 in table

Notes

  • 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.

Bayonet joint: two studs in L-slots, locked by a 30° turn size chart

parametervalue
tubeØ20
studs2 × Ø3
slot8 axial + 30° turn, 3 wide
lock30° turn

Where the files are

Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.

Henry T. Brown (1868, public domain)Five Hundred and Seven Mechanical Movements — scan on archive.orgwebPublisher's page; dimensions are facts
507movements.comBrown's movement No. 245: figure, his text and an animationwebPublisher's page; dimensions are facts

Free files

★ Free files 1 parts. Xem Studio design: free to use, print and sell things from; not to be republished as files. Xem Studio Design License. index.json

bayonet-joint-mechanism-assemblyAssembled mechanism, all parts placed at one pose (STEP keeps each part separate)STEP · STL
Let your AI pull this. Add https://xemstudio.com/mcp to Claude, ChatGPT, Cursor or any MCP client (free, no account, one minute) and it can look up exact sizes, mating fits and free STEP/STL from every chat.
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Plain text: sheet.txt · JSON: /api/geometry?object=bayonet-joint-mechanism

Bayonet joint: two studs in L-slots, locked by a 30° turn, isometric render of a generated part
Render of bayonet-joint-mechanism-assembly from the free STEP; not to scale.

Fits with

Bayonet tube Ø20 × Ø14 × 70 with two Ø3 stud holes, isometric render of a generated part
Bayonet tube Ø20 × Ø14 × 70 with two Ø3 stud holes20.0×20.0×70.0 mm★ 1 file
Bayonet socket Ø24 × Ø20 × 40 with two L-slots (8 deep, 30° turn), 3 wide, isometric render of a generated part
Bayonet socket Ø24 × Ø20 × 40 with two L-slots (8 deep, 30° turn), 3 wide24.0×24.0×40.0 mm★ 1 file
Dowel pins, 2–6 mm (ISO 2338 / DIN 6325), isometric render of a generated part
Dowel pins, 2–6 mm (ISO 2338 / DIN 6325)5 sizes★ 23 files

Questions

How does a bayonet joint lock?

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.