millwork. Of the edge joints shown in figure 3-50,
the dowel and spline joints are used mainly in
furniture and cabinet work, whereas the plain butt and
the tongue-and-groove joints are used in practically
all types of woodworking.
The joints used in rough and finished carpentry
are, for the most part, simply nailed together. Nails in
a 90° plain butt joint can be driven through the
member abutted against and into the end of the
abutting member. The joints can also be toenailed at
an angle through the faces of the abutting member
into the face of the member abutted against, as shown
in figure 3-51. Studs and joists are usually toenailed
to soleplates and sills.
The more complex furniture and cabinet-making
joints are usually fastened with glue. Additional
strength can be provided by dowels, splines,
corrugated fasteners, keys, and other types of joint
In the dado joint, the gain joint, the
mortise-and-tenon joint, the box corner joint, and the
dovetail joint, the interlocking character of the joint is
an additional factor in fastening.
All the joints we have been mentioned can be cut
either by hand or by machine. Whatever the method
used and whatever the type of joint, remember: To
ensure a tight joint, always cut on the waste side of the
line; never on the line itself. Preliminary grooving on
the waste side of the line with a knife or chisel will
help a backsaw start smoothly.
For half-lap joints, the members to be jointed are
usually of the same thickness, as shown in figure 3-43.
The method of laying out and cutting an end butt half
lap (figure 3-43) is to measure off the desired amount
of lap from each end of each member and square a
line all the way around at this point. For a corner half
lap (figure 3-43), measure off the width of the
member from the end of each member and square a
line all the way around. These lines are called
Next, select the best surface for the face and set a
marking gauge to one-half the thickness and score a
line (called the cheek line) on the edges and end of
each member from the shoulder line on one edge to
the shoulder line on the other edge. Be sure to gauge
the cheek line from the face of each member. This
ensures that the faces of each member will be flush
after the joints are cut.
Next, make the shoulder cuts by cutting along the
waste side of the shoulder lines down to the waste side
of the cheek line. Then, make the cheek cuts along the
waste side of the cheek lines. When all cuts have been
made, the members should fit together with faces,
ends, and edges flush or near enough to be made flush
with the slight paring of a wood chisel.
Other half-lap joints are laid out in a similar
The main difference is in the method of
cutting. A cross half-lap joint may best be cut with a
dado head or wood chisel rather than a handsaw.
Others may easily be cut on a bandsaw, being certain
Figure 3-50.-Edge Joints.