The rivet squeezer shown in figure 4-11 is the
Larger rivets require greater air pressure. The
pneumatic type.
approximate air pressures for four of the most common
rivet sizes are given in table 4-1.
DRILLS
Table 4-1.--Approximate Air Pressure for Rivet Guns
As is commonly known, drills are used to bore
holes. In the following paragraphs, the correct use and
Rivet Size
Air Pressure (PSI)
some common errors in the usage of drills are
3/32
35
presented. Additionally, a brief description of
pneumatic and angle-drive drills is included.
1/8
40
5/32
60
Portable Drills
Before using a drill, turn on the power and check it
ONE-SHOT GUN.--The one-shot gun is de-
for trueness and vibration. Do not use a drill bit that
signed to drive the rivet with just one blow. It is larger
wobbles or is slightly bent. You can visually check a
and heavier than other types and is generally used for
drill bits trueness by running the motor.
heavy riveting. Each time the trigger is depressed, the
The most common error made by the inexperienced
gun strikes one blow. This gun is rather difficult to
person is to hold a portable drill at an incorrect angle to
control on light-gauge metals. Under suitable
the work. Make sure the drill is held at right angles to
conditions, it is the fastest method of riveting.
the work. When you are drilling in a horizontal
SLOW-HITTING GUN.--The slow-hitting gun
position, you can see if the drill is too far to the right or
has a speed of 2,500 bpm (blows per minute). As long
left, but it is difficult to tell if the rear of the drill is too
as the trigger is held down, the rivet set continues to
high or too low. Until you learn how to hold a drill at the
strike the rivet. This gun is widely used for driving
correct angle, another person should sight the angle
medium-sized rivets. It is easier to control than the
before starting the drill.
one-shot gun.
Another common mistake is to put too much
FAST-HITTING GUN.--The fast-hitting gun
pressure on the drill. Pushing or crowding a drill may
strikes the rivet with a number of relatively lightweight
break the drill point. It could cause the drill to plunge
blows. It strikes between 2,500 and 5,000 bpm and is
through the opposite side of the sheet and leave rough
generally used with the softer rivets. Like the
edges around the hole. It could also cause the drill to
slow-hitting gun, it continues to strike the rivet head as
sideslip on the metal, causing hole elongation.
long as the trigger is depressed.
The drill should not be stopped immediately upon
CORNER RIVETER.--The corner riveter is so
breaking through. It should continue to be inserted for
named because it can be used in corners and in close
approximately half its length while still running, and
quarters where space is restricted. The main difference
then withdrawn. This operation requires judgment and
between this riveter and the other types is that the set is
skill because it is very easy to ream the hole. If this is
very short and can be used in confined spaces. See
done properly, cleaner holes will result.
figure 4-11.
Pneumatic Drills
SQUEEZE RIVETER.--The squeeze riveter
differs from the other riveters in that it forms the rivet
Pneumatic drills are available in various sizes and
head by means of squeezing or compressing instead of
shapes. The drills are designed to provide a rotary shaft
by distinct blows. Once it is adjusted for a particular
that is equipped with a chuck capable of holding a drill
type of work, it will form rivet heads of greater
bit. Most drills are powered by a vane air motor; speed
uniformity than the riveting guns. It is made both as a
is adjustable by using the variable restrictor built into
portable unit and as a stationary riveting machine. As a
the motor body. Normal maintenance of the unit
portable unit, it is larger than the riveting guns and can
requires only a clean, dry air supply and periodic
be used only for certain types of work that will fit
lubrication of the vane assembly. Lubrication can be
between the jaws. The stationary, or fixed jaw contains
accomplished by inducing a small amount of light oil
the set and is placed against the rivet head in driving.
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