A DRIVE SLIP JOINT is a method of joining two
flat sections of metal. Figure 2-61 is the pattern for the
drive slip. End notching and dimensions vary with
application and area practice on all locks, seams, and
S joints are used to join two flat surfaces of
metal. Primarily these are used to join sections of
rectangular duct. These are also used to join panels in
air housings and columns.
Figure 2-62 shows a flat S joint. View A is a
pattern for the S cleat. View B is a perspective view
of the two pieces of metal that form the flat S joint.
In view C, note the end view of the finished S joint.
Figure 2-63 shows a double S joint. View B is
the pattern for the double S cleat. View A is one of
two pieces of metal to be joined. Note the cross section
of a partially formed cleat and also the cross section
of the finished double S joint. his is a variation of
Figure 2-61.Drive slip pattern and connections
Figure 2-62.S joint or slip pattern and connections.
Figure 2-63.Double S joint (cleat) pattern.
the simple flat S and it does not require an overlap
of metals being joined.
Figure 2-64 shows a standing S joint. View B is
the pattern for the standing S cleat. View A is one of
the two pieces of metal to be joined. Note the cross
section of the finished standing S cleat and standing
Many kinds of seams are used to join sheet-metal
sections. Several of the commonly used seams are
shown in figure 2-65. When developing the pattern,
ensure you add adequate material to the basic
dimensions to make the seams. The folds can be made
by hand; however, they are made much more easily on
a bar folder or brake. The joints can be finished by
soldering and/or riveting.
When developing sheet-metal patterns, ensure
you add sufficient material to the base dimensions to
make the seams. Several types of seams used to join
sheet-metal sections are discussed in this section.
There are three types of lap seams: the PLAIN
LAP seam, the OFFSET LAP seam, and the CORNER
LAP seam (fig. 2-66). Lap seams can be joined by
drilling and riveting, by soldering, or by both riveting
and soldering. To figure the allowance for a lap seam,
you must first know the diameter of the rivet that you
plan to use. The center of the rivet must be set in from
the edge a distance of 2 1/2 times its diameter;
therefore, the allowance must be five times the
diameter of the rivet that you are using. Figure 2-67
shows the procedure for laying out a plain lap and a
comer lap for seaming with rivets (d represents the
diameter of the rivets). For comer seams, allow an
additional one sixteenth of an inch for clearance.