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.
A pair of decent safety wire...
A pair of decent safety wire pliers is a must if you're going to be doing it with any regularity. This is the 9-inch pair offered by Graham Tool Co and features reversible action handy for both left- and right-hand twists. The other item necessary is a spool of safety wire. Pictured is a 1lb spool of 0.032-inch military spec stainless steel safety wire. This conforms to the military MS-20995-C and government QQW432 specs. What does that mean? Basically it means that it's the highest quality safety wire available and meets the FAA, military, and the NTSB requirements for use in aircraft.
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.
 A bolt head jig provides a...  A bolt head jig provides a fast, simple way to drill bolt heads with virtually no broken drill bits. Made of 6061 T6 hard anodized aluminum, the jig fits bolt diameters from 3/16- to 5/8-inch and works on hex head, 12-point countersunk, and Allen head cap screws. |  To drill the head of the bolt,...  To drill the head of the bolt, a 5/64-inch drill bit is guided by a bushing to ensure that the resulting hole is true. |  |
 To drill the threaded portion...  To drill the threaded portion of a fastener, a different drill jig is necessary. Using a 5/64-inch drill bit, fasteners ranging in size from 1/4 to 3/8 inch can be drilled for use with safety wire. |  While bolts up to 5/8 inch...  While bolts up to 5/8 inch can be drilled using the bolt... |  ...head jig, such as this...  ...head jig, such as this 5/8-inch Allen head bolt larger hardware needs to be drilled using a more universal jig. |