Xem Studiomeasured geometry

Library › Joinery › Scarf & splice joints ·

Finger splice joint (finger joint for lengthening)

What is a finger splice joint? · Hardware · basis: Xem Studio design — geometry computed in the generator from traditional proportions

Also called: finger splice, finger joint lumber, finger jointed, comb splice, empalme dentado, Keilzinkung, Keilzinkenverbindung

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

length
140.0 mm
width
20.0 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).
  • Tapered interlocking fingers join two members end to end — how long lumber is made from short pieces.

Finger splice joint size chart

dimensionvalue
stock20 × 20 mm square
partspart a, part b
fingers4 across the width, 20 mm long, tapered
assemblespushed together end to end
holdswith glue; huge glue area in a short length

Where the files are

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

Xem StudioJoinery design (geometry computed in the generator from traditional proportions)webXem Studio design

Free files

★ Free files 3 parts. Xem Studio design: free to use, print and sell things from; not to be republished as files. Xem Studio Design License. index.json

finger-splice-joint-part-aMember A with four tapered fingersSTEP · STL
finger-splice-joint-part-bMember B with the matching fingersSTEP · STL
finger-splice-joint-assembledAll 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=finger-splice-joint

Finger splice joint (finger joint for lengthening), isometric render of a generated part
Render of finger-splice-joint-assembled from the free STEP; not to scale.

Fits with

Box joint (finger joint), isometric render of a generated part
Box joint (finger joint)90.0×60.0×90.0 mm★ 3 files
Plain scarf joint (1:4), isometric render of a generated part
Plain scarf joint (1:4)200.0×20.0×20.0 mm★ 3 files

Questions

Where is a finger splice used?

To lengthen members: finger-jointed lumber, long printed rails made from short prints.