OK. You’ve finished twisting and turning. Now what? That’s easy. Cut off the excess length (the excess length is often called the “pigtail” or “tab”). The idea is to leave approximately 0.500-inch of twisted wire sticking out on the back-side of the last bolt or fastener. With a set of pliers, bend this material back onto itself, forming a loop (hence the term “pigtail”). You want the rounded portion of the loop to be what comes in contact with your hands, clothing or whatever. Let’s just say the rounded pigtail is less band-aid dependent than a raw edge of twisted safety wire.

AIRCRAFT PRACTICES…

The aircraft industry is full of established methods of making things work. What follows is a look at how to correctly safety wire fasteners, using proven techniques:

Illustration 1	Illustration 2	Illustration 3	Illustration 4

Illustrations 1, 2, 3 and 4 apply to all types of bolts, fillister head screws, square head plugs and other similar parts that are wired together. The idea in each of these cases is to insure that the loosening tendency of either part in counteracted by the tightening of the other part. According to the Standard Aviation Maintenance Handbook: “The direction of twist from the second to the third unit is counterclockwise to keep the loop in position against the head of the bolt. The wire entering the hole in the third unit will be the lower wire and by making a counterclockwise twist after it leaves the hole, the loop will be secured in place around the head of that bolt.”

Illustration 5	Illustration 6	Illustration 7	Illustration 8

Illustrations 5, 6, 7 and 8 show the accepted aircraft methods for wiring various standard items. In these examples the wire may be wrapped over the unit rather than around it, particularly when wiring castellated nuts or other items where a clearance problem may exist.

Illustration 9

Illustration Number 9 is different. It shows the correct procedure for safety wiring bolts in different planes. As with other safety-wiring tasks, the wire should always be applied so that the tension is in the direction of tightening. Illustration Number 9, shows the method used for hollow head plugs. As pointed out previously, the “pigtail” or tab should be bent inside the hole to avoid snags and possible injury to anyone working on the car.

Illustration 10

If you have a group of fasteners that are closely spaced they can be wired together, as shown in Illustration 10. With this many components safetied with one wire, there is a possibility for loosening. As a result, the aircraft industry has a rule of thumb for such a group of fasteners. It states you should limit the number of units that may be wired with a piece of wire 24-inches long.

One final tip when it comes to safety wire: Think about carrying a mechanic’s magnet with you when safety wiring pieces together. Why? Simple. Cut-off wire from the pigtail ends has a nasty habit of ending up in places it shouldn’t be – and that includes tires. Remember, the pigtail cut-offs are sharp!