Boxes, frames
Splined / keyed miter
A miter with a spline in the joint, or keys sawn in after the glue.
Use when
- You want the miter look and a real glue surface.
Don’t use when
- Do not skip the spline on a box that will be picked up by one side.
- Keep
- Waste, hatched on the drawing
- Dimension
- Long parts are broken. The 1 in bar is true scale.
Stock
Thickness steppers move by 1/16 in, or 0.5 mm. You can type 3/4 or 1-1/8.
Sizes
| Mark | Size | Rule |
|---|---|---|
| Miter | 45° | 45° each, for a square corner |
| Spline thickness | 1/8 in | 1/8 in spline across the miter |
| Spline width | 3/4 in | 3/4 in across both faces |
| Spline grain | across the joint | Grain of a spline runs across the joint, not along it |
Cut sequence
1Miter, then groove
45°, then a groove 1/8 in by about 3/4 in across the miter.
2Fit a cross-grain spline
The spline grain runs across the joint. It should not bottom out in both grooves at once.
3Dry-fit, then glue
Close the joint dry. Check that shoulders and faces meet, then glue. If this is a frame or a box, check both diagonals before the glue grabs.
Stop when: Dry-fit is tight with hand pressure, square, and the diagonals match.
Glue
End grain to end grain
Strength
furniture
Movement
The spline crosses the miter, so the glue is no longer only end grain.