grip length is less than the shank diameter. Hi-shear
rivets are shown in figure 3-5.
Hi-shear rivets are identified by code numbers
similar to the solid rivets. The size of the rivet is
measured in increments of thirty-seconds of an inch for
the diameter and sixteenths of an inch for the grip
length. For example, an NAS1055-5-7 rivet would be a
hi-shear rivet with a countersunk head. Its diameter
Figure 3-6.--Sectional view of rivnut showing head and end
would be 5/32 of an inch and its maximum grip length
designs.
would be 7/16 of an inch.
The collars are identified by a basic code number
Q3-5.
When space is too restricted to properly use a
and a dash number that correspond to the diameter of
bucking bar, what type of rivet should be
the rivet. An A before the dash number indicates an
used?
aluminum alloy collar. The NAS528-A5 collar would
be used on a 5/32-inch-diameter rivet pin. Repair
Q3-6.
Hi-shear (pin) rivets are available in what
procedures involving the installation or replacement of
two head styles?
hi-shear rivets generally specify the collar to be used.
FASTENERS (SPECIAL)
Rivnuts
Fasteners on aircraft are designed for many
The rivnut is a hollow rivet made of 6063
different functions. Some are made for high-strength
aluminum alloy, counterbored and threaded on the
requirements, while others are designed for easy
inside. They are manufactured in two head styles, flat
installation and removal.
and countersunk, and in two shank designs, open and
closed ends. See figure 3-6. Each of these rivets is
Lock-Bolt Fasteners
available in three sizes: 6-32, 8-32, and 10-32. These
numbers indicate the nominal diameter and the actual
Lock-bolt fasteners are designed to meet
number of threads per inch of the machine screw that
high-strength requirements. Used in many structural
fits into the rivnut.
applications, their shear and tensile strengths equal or
exceed the requirements of AN and NAS bolts.
Open-end rivnuts are the most widely used, and are
recommended in preference to the closed-end type.
The lock-bolt pin, shown in view A of figure 3-7,
However, in sealed flotation or pressurized
consists of a pin and collar. It is available in two head
compartments, the closed-end rivnut must be used.
Q3-1.
Solid rivets are classified according to what
three factors?
Q3-2.
A rivet with the code number MS 20426 has
what type of rivet head?
Q3-3.
What code identifies a rivet with a plain head
marking?
Q3-4.
Rivets used primarily for joining magnesium
alloy structures have what alloy designation?
Figure 3-7.--Lock bolts.
Figure 3-5.--Hi-shear rivet.
3-4
