• Never depend on plastic-dipped handles to insulate you from electricity. They are intended for comfort and improved grip, not protection against electric shock. 2.3.9 Repair or Replace? While repairing pliers is not recommended, regular maintenance is important. Dull cutting knives may be sharpened, and the hinge should adjustment of jaw size by merely squeezing the handles. See Figure 2-18. Some types of adjust- able pliers may not have a locking feature. 2.3.7 Locking Pliers Locking pliers are available with straight or curved jaws, in a variety of sizes, Figure 2-19. These pliers use a compound leverage system to lock the jaws for holding various shapes and sizes of work. It is a combination tool that functions as pliers, wrench, portable vise, or clamp. Because of their clamping power, locking pliers can free both hands for doing other work (such as brazing, sawing, or drilling). Locking pliers can some- times be used to unscrew fasteners that have stripped or rounded heads. Since they will mar surfaces, however, locking pliers should never be used on good nuts and bolts. Attempts to repair this tool are not recommended. 2.3.8 Using Pliers Safely • Never use pliers to do the job of another tool. • Never push pliers beyond their capacity. Bending stiff wire with light pliers or the tip of needle-nose pliers can spring or break the tool. • Never expose pliers to excessive heat. Direct flame on metal can draw the temper and ruin the tool. Cutting pliers are especially vulner- able to high heat. • Never cut hardened wire with ordinary pliers. Also, never rock pliers from side to side when cutting wire, nor bend the wire back and forth against the cutting knives. These practices can dull or nick cutting edges. • Never cut any wire or metal unless your eyes and your fellow workers’ eyes are protected. Safety goggles are an absolute must. Goodheart-Willcox Publisher Figure 2-17. Slip-joint pliers are an “all-purpose” tool for gripping and holding objects. Goodheart-Willcox Publisher Figure 2-18. This type of adjustable pliers offers one- handed operation. Jaw size adjustment is done auto- matically when the handles are squeezed. Goodheart-Willcox Publisher Figure 2-19. Locking pliers are versatile and can be used to hold objects, freeing both hands for other tasks. They are available with several types of jaws. Chapter 2 Hand Tools 23 Copyright Goodheart-Willcox Co., Inc.