Lineman's pliers

Lineman's pliers (US English), also known as linesman pliers, combination pliers (UK / US English), or "Kleins" (a genericized trademark in North America), are pliers commonly used by lineworkers and electricians for gripping, twisting, bending, and cutting wire, cable, and small metal components.^[1] Their design provides a high mechanical advantage, allowing significant gripping and cutting force to be applied at the jaws.

Lineman's pliers typically have a flat gripping surface at the tip of the jaws. By contrast, combination pliers usually have a shorter flat section and a concave gripping area designed for holding round stock such as metal rods. Both types typically include a beveled cutting edge near the pivot, similar to that of diagonal pliers. Some models also incorporate additional gripping, crimping, or wire-shearing features near the handle side of the joint. Designed for potentially heavy manual operation, these pliers typically are machined from forged steel and the two handles precisely joined with a heavy-duty rivet that maintains the pliers' accuracy even after repeated use under extreme force on heavy-gauge wire. They typically include coated handles for improved grip. Some handles provide electrical insulation, although many models are not rated for use on live circuits. Some pliers are certified to withstand a specified voltage, e.g. 1000 V.^[2]

Variants of lineman's pliers are also used in some glassworking shops for manipulating and breaking glass components.^[3]

Like most hand tools, the durability and service life of pliers depend on load, frequency of use, design, and manufacturing quality. They may be forged out of alloyed or unalloyed tool steel. For basic quality pliers unalloyed tool steel with a relatively low carbon content of 0.45% may be used. Top-quality pliers are typically made from higher carbon tool steel and alloyed with elements such as chromium, vanadium and molybdenum.^[4][5] In addition to being suitable for cutting soft copper and aluminum, pliers may be specifically designed for cutting hardened wire, such as piano wire or nails, by induction hardening of the cutting edges.^[6]

Lineman's pliers are used in the electrical trade to cut, straighten, and bend wire, and also to twist wires together when making splices. Lineman's pliers can also strip insulation from wire and some cables, although dedicated wire strippers are generally preferred because they remove insulation more quickly and with less risk of damaging the conductor. They can also be used to pull fish tape through long runs of conduit where the high friction makes it difficult to pull it by hand. Some pliers are equipped with a crimping tool for the purpose of compressing crimp connections.^[7]

Lineman's pliers can be used to bend or straighten sheet metal components, especially in cases where smaller pliers don't offer enough mechanical advantage. The square nose and flat sides of lineman's pliers are particularly useful for forming precise right-angle bends. The durability of these pliers allows them to be used for tasks like removing nails and other types of fasteners.^[8]

Lineman's pliers are similar to needle-nose pliers: both tools share a typically solid, machined forged steel construction, durable pivot, gripping nose and cutting craw. The main differences are that the slender nose of the needle-nose pliers enable it to form small diameter bends, and position or support items in awkward places. Needle-nose pliers typically have a lower handle/nose length ratio, reducing the force that can be exerted at the tip. Also, needle-nose pliers tend to be available in smaller sizes (for electronics applications, they may be found as small as 1/10 scale of the full-size version).^[9]

Lineman's pliers may be used to cut steel screws up to #10, and virtually any dry-wall screw, although the thread form will be distorted. Lineman's pliers sometimes include an integrated crimping device in the craw of the handle side of the pliers' joint.^[8]

Lineman's pliers have a tapered nose suitable for reaming the rough edge of a 1⁄2-inch (13 mm) or larger conduit, or cleaning sharp metal from the inside of a standard metal knockout in an electrical enclosure such as a junction box or breaker panel. Some brands manufacture pliers (i.e. Ideal) with a narrower jaw, suitable for reaming out smaller conduit.^[8]