Used for construction such as framework and softwood joinery, halving joints have little structural integrity. Strength comes from glue or reinforcing screws, while shoulders increase rigidity. Half the thickness is cut away on one component, a corresponding section removed on the second. Wood should be straight-grained and defect-free, so you can clear waste cleanly. Variations include the corner (‘L’) , cross (‘X’), dovetail and halving.
Tools you need
- 2H pencil
- Tenon saw
- Steel rule
- Try square
- Marking gauge
- Smoothing plane
- Marking knife
How To Make A T-halving joint
1.Mark the width of the joint on the first piece (A) with a pencil. For accuracy, hold the second piece (B) in position and mark next to each edge. Continue the pencil lines across piece A with a try square.
2. Carefully mark a line around the end of piece B, which will be the tenon. Its distance from the end of the timber is the width of piece A, plus 1 mm (1/32 in) extra. Continue the pencil lines down the edges of piece B using the square. Make sure you hold the square against relevant face sides and face edges.
3.Using a steel rule, set the marking gauge to half the thickness of the timber. Check this for accuracy by marking from each side on an offcut. To make minute adjustments to the gauge, tap either end on the bench top, depending on whether you want to increase or decrease the gap.
4.Mark the sides of the joint on both pieces. Pencil in the waste sections that you need to remove with the chisel. This will prevent you from cutting into the wrong side of the wood.
5. Cramp piece A to the bench. Using a tenon saw, cut across the shoulders, keeping the blade just to the waste side of the pencil lines. A tip is to start the cut by scoring a line with a marking knife and chiselling a shallow V. This provides a channel for the teeth of the saw to run in. With some practice, you will find this unnecessary.
6. Use a sharp chisel and mallet to remove the waste between the shoulder lines. Make several shallow cuts, starting about 3 mm (A in) down from the top. Hold the handle lower than the blade, which should be pointing up slightly. This helps to stop the wood splitting out at the back.
7. Chop out the waste until you reach the gauged line, then turn the wood over and repeat the process from the other side. This will leave a bump, which you can pare off level with as-wide-a chisel as possible for flatness.
8. Grip the tenon piece (B) in the vice, tilted away from you. With the saw horizontal, carefully cut down the cheek, just inside the gauged line. Reverse the work piece and cut from the other side. Reposition the tenon so that it is upright in the vice and cut down to the shoulder line.
9. Cramp piece B to the bench and carefully pare away remaining waste. Use the chisel either with the grain or across it. Check the surface is flat, then try fitting the two halves of the joint together. If it is too tight, take a shaving off the edge of part B with a finely set smoothing plane.
10.Apply glue, evenly, to the faces that will meet, using a brush. Cramp together, using packing pieces from scrap wood to prevent dents. Check the shoulders are tight and finally tighten the cramp. When the glue is dry, place the joint in the vice and plane off the protruding lip of the tenon.
A halving joint is quiok and easy to make with a router, especially if you have several identical components. Hold them together with a sash cramp and temporarily pin (or cramp) a dead straight batten across them, checking with the square that it is at 90 degrees. The batten acts as a guide for the base of the router, which should be fitted with a straight outter.
Word Discription :
Cheek The side of a tenon.
Rail A horizontal piece of wood in a frame, usually between two vertical stiles.
Stile The vertical sides of a frame.
Stock Prepared timber, planed all round and ready to be worked.