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Butterfly key (bow-tie, dutchman)

Name: Butterfly key (bow-tie, dutchman) dimension sheet
Creator: Xem Studio
License: https://creativecommons.org/licenses/by/4.0/

What size is a butterfly key? · Hardware · basis: Xem Studio design — geometry computed in the generator from traditional proportions

Also called: butterfly key, bow tie key, dutchman joint, butterfly joint, bowtie inlay, llave mariposa, mariposa de madera, Schwalbenschwanz-Einlage, Holzschwalbe

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

length: 80.0 mm
width: 80.0 mm
height: 20.0 mm

Notes

Woodworking joint drawn for 3D printing: the parts lock together by shape, so a print can be joined without glue or screws. Drawn at true size with the parts line to line (zero gap) in their assembled position — add your printer's fit allowance to the mating faces (your AI or slicer can do this).
A bow-tie shaped key let into the surface across a joint or a crack.

Butterfly key size chart

dimension	value
stock	20 mm boards edge to edge
parts	board a, board b, key
key	40 long, 16 at the ends, 8 at the waist, 8 mm deep
assembles	boards together, key pressed in from above
holds	the two boards (or a crack) from pulling apart

Where the files are

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

Xem Studio

Joinery design (geometry computed in the generator from traditional proportions)

web

Xem Studio design

Free files

★ Free files 4 parts. Xem Studio design: free to use, print and sell things from; not to be republished as files. Xem Studio Design License. index.json

butterfly-key-joint-board-a	Board with half the bow-tie socket	STEP · STL
butterfly-key-joint-board-b	Board with the other half	STEP · STL
butterfly-key-joint-key	Bow-tie key, 8 mm deep	STEP · STL
butterfly-key-joint-assembled	All parts in their assembled position (each part its own solid)	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.

Set it up →

Plain text: sheet.txt · JSON: /api/geometry?object=butterfly-key-joint