ADJUSTABLE WRENCHES

ADJUSTABLE WRENCHES A handy all-round wrench that is generally included in every toolbox is the adjustable open-end wrench. This wrench is not intended to take the place of the regular solid open-end wrench. Additionally, it is not built for use on extremely hard-to-turn items. Its usefulness is achieved by being capable of fitting odd-sized nuts. This flexibility is achieved although one jaw of the adjustable open-end wrench is fixed, because the other jaw is moved along a slide by a thumbscrew adjustment (fig. 1-35). By turning the thumbscrew, you can adjust the jaw opening to fit various sizes of nuts. Adjustable wrenches are available in varying sizes, normally ranging from 4 to 24 inches in length. The size of the wrench selected for a particular job is dependent upon the size of the nut or bolt head to which the wrench is to be applied. Adjustable wrenches are often called "knuckle busters," because mechanics frequently suffer these consequences as a result of improper usage of these tools. To avoid accidents, follow four simple steps. First, choose a wrench of the correct size; that is, do not pick a large 12-inch wrench and adjust the jaw for use on a 3/8-inch nut. This could result in a broken bolt and a bloody hand. Second, be sure the jaws of the correct-size wrench are adjusted to fit snugly on the nut. Third, position the wrench around the nut until the nut is all the way into the throat of the jaws. If the wrench is not used in this manner, the result is apt to be as bloody as before. Fourth, pull the handle toward the side having the adjustable jaw (fig. 1-36). This will prevent the adjustable jaw from springing open and slipping off the nut. If the location of the work will not allow for all four steps to be followed when using an adjustable wrench, then select another type of wrench for the job. Union Nut Wrench The adjustable union nut wrench (fig.1-37) is used to assemble and disassemble pipe union nuts. The adjustable jaws are held in place by removable nut and bolt and is adjusted to proper size before each use. In rotating or holding round work, an adjustable pipe wrench (Stillson) may be used (fig. 1-38). The 1-25 Figure 1-36.—Proper procedure for using adjustable wrenches. Figure 1-35.—Adjustable wrenches. HANDLE MOVABLE JAW BOLT NUT ABEf0114 Figure 1-37.—Union nut wrench. Figure 1-38.—Adjustable pipe wrench.