Trestle stretchers
Tusk tenon
A through tenon with a wedge so the stretcher can come apart.
Use when
- The base should knock down.
Don’t use when
- Do not drive the wedge before the shoulder is home.
- 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 |
|---|---|---|
| Tenon thickness | 1/2 in | Half to 0.6 of the stretcher, nearest bit |
| Past the post | 1-1/2 in | 1-1/4 to 2 in, so the wedge has a mortise to sit in |
| Tenon length | 3-1/4 in | Post thickness plus the projection |
| Wedge start | 1/8 in | The wedge mortise starts 1/8 in past the post face, so driving the wedge draws the shoulder up |
| Cheek | 1/4 in | What is left on the stretcher |
Cut sequence
1Mortise the post through
Tenon 1/2 in. The tenon projects 1-1/2 in.
2Saw the wedge mortise in the tenon
It starts 1/8 in past the far face, so the wedge draws the shoulder tight.
Stop when: The wedge seats and the shoulder is closed. You can knock it back out.
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
Mostly mechanical
Strength
structural
Movement
A tusk tenon comes apart. The wedge draws the shoulder tight. Glue is optional, and usually a mistake if you want it to knock down.