All parts in their assembled position (each part its own solid)

Exact dimensions. True size, no printing tolerance added. Threads are plain cylinders at the major diameter.

STEP STL free, Xem Studio Design License — Xem Studio

Dimensions

dimension	spline
value	3 mm thick, 18 mm along the mitre, 10 mm across it, hidden inside

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 →

From the full sheet

Splined mitre joint (hidden spline): every size, notes, mating features and sources. How big is the spline in a mitre joint?

Other sizes

Mitred member A with a spline slot
Mitred member B with a spline slot
Spline 18 × 10 × 3 mm