Step 1. Assemble the unit. Torque the bolts and
carefully align the safety wire holes.
Step 2. Insert the proper size wire through the
hole in the first bolt.
Step 3. Bend the left end of the wire clockwise
around the bolt head and under the other end of the
Step 4. Pull the loop tight against the bolt head.
Grasp both ends of the wire. Twist them in a clockwise
direction until the end of the braid is just short of the
Step 5. Check to ensure that the loop is still
tightly in place around the first bolt head. Grasp the
wire with pliers just beyond the end of the braid. While
holding it taut, twist it in a clockwise direction until the
braid is stiff.
The braid must be tight enough to resist
Step 6. Insert the upper end of the safety wire
through the hole in the second bolt. Pull the braid until
it is taut.
Step 7. Bring the other end of the wire counter-
clockwise around the bolt head and
protruding wire end.
Step 8. Tighten the loop and braid the wire ends in
a counterclockwise direction. Grasp the wire with the
pliers just beyond the end of the braid and twist in a
counterclockwise direction until the braid is stiff. Make
sure you keep the wire under tension.
With a final twisting motion, bend the
braid to the right and against the head of the bolt.
Step 10. Cut the braid, being careful that between
three and six full twists still remain. Avoid sharp
Figure 5-23 shows various methods commonly
used in safety wiring nuts, bolts, and screws. Examples
1, 2, and 5 of figure 5-23 show the proper method of
safety wiring bolts, screws, square head plugs, and
similar parts when wired in pairs. Examples 6 and 7
show a single-threaded component wired to a housing
or lug. Example 3 shows several components wired in
series. Example 4 shows the proper method of wiring
castellated nuts and studs. Note that there is no loop
around the nut. Example 8 shows several components
in a closely spaced, closed geometrical pattern, using
the single-wire method.
When drilled-head bolts, screws, or other parts are
grouped together, they are more conveniently safety
wired to each other in a series rather than individually.
The number of nuts, bolts, or screws that may be safety
wired together depends on the application. For
instance, when you are safety wiring widely spaced
bolts by the double-twist method, a group of three
should be the maximum number in a series.
When you are safety wiring closely spaced bolts,
the number that can be safety wired by a 24-inch length
of wire is the maximum in a series. The wire is arranged
in such a manner that if the bolt or screw begins to
loosen, the force applied to the wire is in the tightening
Figure 5-23.Safety wiring methods.
The FAA is working with its aviation security partners in...