The plain butt joint is the simplest and the one
most used by the HT.
An important skill to master is wood joinery. In
The doweled joint is usually a plain butt joint
woodworking, joinery is the art of combining two or
that has been given greater strength with wooden
more pieces of material into one. The purpose for
dowels. Dowels also reinforce other joints such as
this procedure is to increase dimensions, strength, or
the miter and half lap.
material alignment. Wood joinery includes the
manufacture of wood joints and the various devices
When choosing a dowel for edge-to-edge use,
or methods used to fasten them together. These
the dowel diameter should be one-third the
methods include glue, screws, and brads.
thickness of the stock you are jointing. Thus,
3/4-inch thick stock would require a 1/4-inch dowel.
A joint is only as strong as its weakest point.
This can be the joints if they are incorrectly made or
The tongue-and-groove joint is stronger than the
if you use the wrong joint. Correct joint usage and
butt or dowel joint. It is used for wood flooring.
proper construction can make the joint the strongest
point of the project.
tongue-and-groove joint. It is easier to make
because two matching grooves and a separate spline
replace the tongue. Minimal strength is gained if
There are four standard methods for joining
the grain direction of the spline is parallel to the
wood stock edge-to-edge. These methods are the
edges, as shown in figure 3-11. A significant
plain butt, dowel, tongue-and-groove, and splined
strength gain results when the grain direction of the
edge joints shown in figure 3-10.
spline is perpendicular to the edges.
The thickness of both the spline and tongue
should be one-third of the material thickness. The
width of the spline should be equal to twice the
material thickness, while the tongue width should be
the same as the thickness. For example, 3/4-inch
stock would require a spline measuring 1/4 inch
thick and 1 1/2 inches wide or a tongue measuring
1/4 inch thick and 3/4 inch wide (fig. 3-11).
Lap joints are shown in figure 3-12. Plain lap
joints are used in all kinds of construction,
particularly if appearance is not a factor. The end
butt half lap is not as strong as the plain lap joint,
but it looks better and requires less space. The
corner half lap works well for framing buildings,
boxes, and cabinets. The cross lap joint joins the
spokes of a wheel pattern.
The scarf joint (fig. 3-13) is a special type of lap
joint that is used to join heavy timbers. For repair
purposes, the recommended slope is 1 in 12. The
cut should slant through the length of a piece of
wood 12 inches for every inch of depth or width.
The end butt joint with fishplates (fig. 3-14) is
useful for joining short members to make long
Figure 3-10.--Edge joints.
pieces. Secure the fishplates with nails, screws,