Frames, aprons, doors
Loose tenon
A separate tenon in two mortises. A Festool Domino or any loose-tenon system is the machine version.
Use when
- You want mortise-and-tenon strength without sawing an integral tenon.
Don’t use when
- Do not leave the mortises short of glue room.
- 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 | 1/4 in | Nearest bit to 1/3 of the stock. 1/4 in (matches a 1/4 in bit) |
| Tenon width | 1-15/16 in | About 2/3 of the rail width |
| Tenon length | 2-1/2 in | 1-1/4 in into each member. A Festool Domino or any loose-tenon system uses the same idea |
| Mortise depth, each | 1-5/16 in | Half the tenon, plus 1/16 in for glue |
| Cheek | 1/4 in | What is left beside the mortise |
Cut sequence
1Mortise both pieces
Chop or rout. The mortise is the same in each member.
Setup: Width 1/4 in, depth 1-5/16 in.
2Fit the loose tenon
Thickness 1/4 in, width 1-15/16 in, length 2-1/2 in. Round the ends if the mortise is routed.
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
Same glue as a mortise and tenon: long grain on the cheeks. The rail can still move a little across its width.