If the holes are located near the edge of the sheet, a hand
punch, similar to the one shown in figure 12-95, can be
used to punch the holes. If the holes are farther away
from the edge, you can use a deep-throated punch
(either hand operated or power driven) or you can drill
the holes. A breast drill used to drill holes for rivets is
shown in figure 12-96. Drill the hole slightly larger than
the diameter of the rivet to provide a slight clearance.
Riveting involves three operations: drawing,
upsetting, and heading. These are illustrated in figure
12-97. A rivet set and a riveting hammer are used to
perform these operations. The procedure for riveting
sheet metal is as follows:
1. Select a rivet set that has a hole slightly larger
than the diameter of the rivet.
2. Insert the rivets in the holes. Rest the sheets to
be joined on a stake or on a solid bench top, with the
rivet heads against the stake or bench top.
Figure 12-95.--A hand punch.
3. Draw the sheets together by placing the deep
hole of the rivet set over the rivet and striking the head
of the set with a riveting hammer. Use a light hammer
for small rivets and a heavier hammer for larger rivets.
4. When the sheets have been properly drawn
together, remove the rivet set. Strike the end of the rivet
LIGHTLY with the riveting hammer. The process of
spreading the end of the rivet to expand it so that it will
hold the sheets together is known as upsetting the rivet.
Do not strike the rivet too hard or else you might distort
the metal around the rivet hole.
5. Place the heading die (dished part) of the rivet
set over the upset end of the rivet and form the head.
Figure 12-96.--Drilling holes with a breast drill.
One or two hammer blows on the head of the rivet set
Figure 12-97.--Drawing, upsetting, and heading a rivet.
12-40