Installing safety wire involves choosing one of two methods. The double-twist method is the most common of the two, while the single-wire method can be more useful for nuts, bolts and other fasteners in closely-grouped configurations. Single-wire applications also include parts for electrical systems and other hard-to-reach places.
For the double-twist method, the diameter of the wire depends on the type of fasteners. Parts with hole diameters exceeding .045 inches require wiring of .032 safety wire inches in diameter. Those with hole diameters between .045 and .062 inch and spacing of fewer than 2 inches between each part require wire double-strand wire of .020 inch in diameter. However, the single-wire method will require the use of the largest safety wire thickness that can fit in the fasteners hole.
Additionally, aluminum wire of .031 inch diameter, copper wire of .020 inch diameter, and similar types of wire including ss safety wire, function as seals on specific forms of equipment. This includes portable fire extinguishers, first-aid kits, emergency valves, and equipment with similar construction.