The flat end of the head is called the face. This
end is used for most hammering jobs. The domed end
of the hammer is called the peen. The peen end is
smaller in diameter than the face, and is useful for
striking in areas that are too small for the face to enter.
Ball peen hammers are made in different weights,
usually 4, 6, 8, and 12 ounces and 1, 1 1/2, and
For most work, a 1 1/2-pound and a
12-ounce hammer will suffice.
MALLETS.A mallet is a soft-faced hammer.
Mallets are constructed with heads made of brass,
lead, tightly rolled strips of rawhide, plastic, or plastic
with a lead core for added weight.
A plastic mallet, similar to the one shown in
figure 13-1, is the type normally found in the AMs
toolbox. The weight of the plastic head may range
from a few ounces to a few pounds; however, the size
of the plastic mallet is measured across the diameter
of the face.
The plastic mallet may be used for
straightening thin sheet ducting or for installing
Rotary Rivet Cutters
In case you cannot obtain rivets of the required
length, rotary rivet cutters may be used to cut longer
rivets to the desired length. See figure 13-2. When
you use the rotary rivet cutter, insert the rivet part way
into the correct diameter hole.
Place the required
number of shims (shown as staggered, notched strips
in the illustration) under the head and squeeze the
handles. The compound action from the handles
rotates the two discs in opposite directions. The
rotation of the discs shears the rivet smoothly to give
the correct length (as determined by the number of
Figure 13-2.Rotary rivet cutter.
shims inserted under the head). When you are using
the larger cutter holes, place one of the tool handles in
a vise, insert the rivet in the hole, and shear it by
pulling the free handle. If this tool is not available,
diagonal-cutting pliers can be used as an emergency
cutter, although the sheared edges will not be as
smooth and even as when they are cut with the rotary
A rivet set is a tool equipped with a die for driving
a particular type of rivet. Rivet sets are used in both
hand and pneumatic hammer riveting methods. Rivet
sets are available to fit every size and shape of rivet
head. The ordinary hand set is made of 1/2-inch
diameter carbon steel about 6 inches long. It is
knurled to prevent slipping in the hand. Only the face
of the set is hardened and polished. Sets for the
oval-head rivets (universal, round, and brazier) are
recessed (or cupped) to fit the rivet head. When you
select a rivet set, be sure that it will provide the proper
clearance between the set and the sides of the rivet
head and between the surfaces of the metal and the
set. Flush or flat sets are used for countersunk and
flat-head rivets. To set flush rivets properly, the flush
sets should be at least 1 inch in diameter.
Special sets, called draw sets, are used to draw
up" the sheets being riveted in order to eliminate any
opening between them before the rivet is bucked.
Each draw set has a hole 1/32 of an inch larger than
the diameter of the rivet shank for which it was made.
Sometimes, especially in hand-working tools, the
draw set and the rivet header are incorporated into one
tool. The header consists of a hole sufficiently
shallow for the set to expand the driven rivet
bucktail and form a head on it when the set is
struck by a hammer.
Figure 13-3 shows a
rectangular-shaped hand set that combines the draw
and header sets and a flush set used with a pneumatic
Sets used with pneumatic hammers (rivet guns)
are provided in many sizes and shapes to fit the type
and location of the rivet. These sets are the same as
the hand rivet sets except that the shank is shaped to
fit into the rivet gun. The sets are made of high-grade
carbon tool steel and are heat-treated to provide the
necessary strength and wear resistance. The tip or
head of the rivet set should be kept smooth and highly
polished to prevent marring of rivet heads.