It's hard to imagine what the automotive world in general would be like if it weren't for the military-industrial complex. Now, while you may be asking yourself, what has the Navy got to do with my F-100, think about it for a minute. The majority of manufacturing techniques, tools, and materials that were commonplace in the 1950s and '60s, were a direct byproduct of things learned by industry during World War Two. The stringent tolerances demanded by the military and the production challenges that came with them enabled automotive manufacturers to more or less learn on the government's dime in a few short years what would have taken them decades and millions of dollars to develop on their own. Building tanks, ships, and aircraft of all shapes and sizes challenged their manufacturing abilities and allowed them to develop new technologies and techniques that are continued today. Better braking systems, more reliable engines, improved electrical components, precise manufacturing; these were all byproducts of what industry learned while they were manufacturing products for the military. During the late '30s and early '40s, the automotive industry accounted for a major portion of aircraft production, going so far as halting automobile production completely by 1942 to concentrate on aircraft and related production. By the time the war was over, the automobile and related industries would be forever changed.

For us truck guys, other than being a neat little bit of history, these military influences have little to do with what we're wrenching on out in the garage. Or so you think.

Take the Allen bolt for instance. Invented in the beginning of the 20th century, its name comes from the Allen Manufacturing Company, who actually applied for the patent in 1943 due to escalating needs by the U.S. government brought on by World War Two.

And how about all those anodized fittings that you have connecting all your fluid transfer hoses? You know, the ones that take those weird, expensive wrenches that are neither a fractional size nor metric but some seemingly random number preceded by a dash? Known as AN fittings, these mil-spec (military specification) fittings also trace their heritage back to World War Two when the Army and Navy agreed upon a single standard for fluid transfer fittings used to connect flexible hose and rigid metal tubing. This designation became the standard in the aerospace industry for decades and has recently found its way into the classic automobile market.

Another aerospace standard that has found its way into the automobile hobby is the practice of "safetying." Familiar to anyone who's ever removed a cotter pin from a ball joint, tie rod, or spindle nut, safetying is defined as securing by various means any nut, bolt, turnbuckle, etc., so that vibration will not cause it to loosen during operation. These practices are not a means of obtaining or maintaining torque, but rather a safety device to prevent the disengagement of hardware. There are three basic methods used in safetying; cotter pins and self-locking nuts, of which are no doubt familiar to most of us, and safety wire. While there may be many of you who are familiar with the practice of safety wire, there is probably a good number who are not. I know I've watched guys do it for years but it's something that I've never seemed to get the hang of. That said, I thought I'd educate myself with help from a few products from Graham Tool Co. and the FAA, and bring you guys along as well.

Safetying 101
Basically, there are two methods of safety wiring; the double-twist method that is most commonly used, and the single-wire method used on screws, bolts, and nuts in a closely spaced or closed-geometrical pattern such as a triangle, square, rectangle, or circle. The single-wire method may also be used on parts in electrical systems and in places that are difficult to reach.