pliers from side to side. The 8″ (203 mm), heavy- duty type is best for refrigeration, heating, and air conditioning work. 2.3.4 Pump Pliers Pump pliers, also known as utility or groove- joint pliers, are used by all types of mechanics. See Figure 2-16. The jaws are positioned and locked into place by engaging the tongue in the proper groove. A series of grooves provides a range of jaw openings up to 4″ (102 mm). Pump pliers will not slip even under heavy pressure. They will grip round, square, flat, and hexagonal objects and can apply limited torque without damage to the work. 2.3.5 Slip-Joint Pliers Slip-joint pliers, Figure 2-17, are an old but still widely used style of pliers. The slip joint provides two jaw positions, and the pliers may have a shear-type wire cutter. These pliers are designed for gripping, turning, and bending. 2.3.6 Adjustable Pliers There are different types of adjustable pliers available. At least one type permits one-handed would be awkward or difficult with any other tool. They are available with or without side cutters. Most long-nose pliers are designed for electrical use but are useful in other ways if not abused. Caution Long-Nose Pliers Damage To avoid damage, never pry with these pliers or try to bend stiff wire with the pliers’ tips. Avoid exposing these pliers to excessive heat the jaw tips will bend outward and render the tool useless. The long-nose pliers recommended for refrigeration, heating, and air conditioning work are the heavy-duty 8″ (203 mm) size, with cutter, in the round pattern. 2.3.3 Diagonal Cutting Pliers Diagonal cutters (often called “dikes”) are designed for cutting electrical wires, cotter pins, nails, and other types of fasteners. See Figure 2-15. When cutting wire, always cut at a right angle to avoid damage to the pliers and do not rock the Goodheart-Willcox Publisher Figure 2-13. Lineman’s, or side-cutting, pliers are a basic item of the technician’s toolbox. Plastic-covered handles, like those shown on these pliers, provide a better grip on the tool. However, plastic handles do not protect against electrical shock. Goodheart-Willcox Publisher Figure 2-14. Long-nose pliers are available in needle-, round-, and flat-nose types. Goodheart-Willcox Publisher Figure 2-15. Diagonal cutting pliers are used for heavier cutting tasks than other types of pliers. Goodheart-Willcox Publisher Figure 2-16. Pump pliers provide a strong, nonslip grip on either round or square objects. 22 Heating and Cooling Essentials Copyright Goodheart-Willcox Co., Inc.