Frames, trestle caps
Bridle / slot mortise
An open mortise on the end of one piece, a tongue on the other.
Use when
- Both pieces meet at the end and you can saw the slot.
Don’t use when
- Do not use a bridle where the slot would show and you wanted it hidden.
- 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 |
|---|---|---|
| Slot thickness | 1/4 in | One third of the thickness, nearest bit. 1/4 in (matches a 1/4 in bit) |
| Slot depth | 2 in | The full width of the mating piece. This joint is open at the end |
| Cheek | 1/4 in | (thickness − slot) / 2 |
| Mating tenon | 1/4 in | The other piece is one tenon, the thickness of the slot |
Cut sequence
1Saw the slot
Slot 1/4 in wide and 2 in deep, open at the end. Cheeks 1/4 in.
2Saw the mating tenon
One tenon, the thickness of the slot, the full width of its board.
Stop when: The end grain of the slot and the tenon end flush.
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
Long grain to long grain
Strength
structural
Movement
A bridle is a mortise and tenon opened at the end. The cheeks are long grain. It shows on the end of the stile.