to cut on the waste side of the lines and making all
lines from the face of the material.
A miter joint is made by mitering (cutting at an
angle) the ends or edges of the members that are to be
joined together (figure 3-44). The angle of the miter
cut is one-half of the angle formed by the joined
In rectangular mirror frames, windows,
door casing boxes, and the like, adjacent members
form a 90° angle, and, consequently, the correct angle
for mitering is one-half of 90°, or 45°. For members
forming an equal-sided figure with other than four
sides (such as an octagon or a pentagon), the correct
mitering angle can be found by dividing the number
of sides the figure will have into 180° and subtracting
the result from 90°. For an octagon (an eight-sided
figure), determine the mitering angle by subtracting
from 90°180° divided by 8 or 90° minus 22.5° equals
67.5°. For a pentagon (a five-sided figure), the angle is
Members can be end mitered to 45° in the wooden
miter box and to any angle in the steel miter box by
setting the saw to the desired angle, or on the circular
saw, by setting the miter gauge to the desired angle.
Members can be edge mitered to any angle on the
circular saw by tilting the saw to the required angle.
Sawed edges are sometimes unsuitable for gluing.
However, if the joint is to be glued, the edges can be
mitered on a jointer, as shown in figure 3-52.
This is a dangerous operation and caution
should be taken.
Since abutting surfaces of end-mitered members
do not hold well when they are merely glued, they
should be reinforced. One type of reinforcement is
the corrugated fastener. This is a corrugated strip of
metal with one edge sharpened for driving into the
joint. The fastener is placed at a right angle to the line
between the members, half on one member and half
on the other, and driven down flush with the member.
The corrugated fastener mars the appearance of the
surface into which it is driven; therefore, it is used
only on the backs of picture frames and the like.
A more satisfactory type of fastener for a joint
between end-mitered members is the slip feather.
This is a thin piece of wood or veneer that is glued
Figure 3-52.-Beveling on a jointer for a mitered edge joint.
into a kerf cut in the thickest dimension of the joint.
First, saw about halfway through the wood from the
outer to the inner corner, then apply glue to both sides
of the slip feather, pushing the slip feather into the
kerf. Clamp it tightly and allow the glue to dry. After
it has dried, remove the clamp and chisel off the
protruding portion of the slip feather.
A joint between edge-mitered members can also
be reinforced with a spline. This is a thick piece of
wood that extends across the joint into grooves cut in
the abutting surfaces. A spline for a plain miter joint
is shown in figure 3-44. The groove for a spline can
be cut either by hand or by a circular saw.
A three-sided recess running with the grain is called
a groove, and a recess running across the grain is called
a dado. A groove or dado that does not extend all the
way across the wood is called a stopped groove or a
stopped dado. A stopped dado is also known as a gain
(figure 3-46). A two-sided recess running along an edge
is called a rabbet T (figure 3-45). Dadoes, gains, and
rabbets are not, strictly speaking, grooves; but joints that
include them are generally called grooved joints.
A groove or dado can be cut with a circular saw as
follows: Lay out the groove or dado on the end wood
(for a groove) or edge wood (for a dado) that will first
come in contact with the saw. Set the saw to the
desired depth of the groove above the table, and set