00104-15 - Module 4: Intro. to Power Tools - Trade Terms and definitions(verified for accuracy)

Abrasive a substance, such as sandpaper, that is used to wear away material Alternating current (AC) The common power supplied to most all wired devices, where the current reverse it's direction may times per second. AC power is the type of power generated and distributed throughout settled areas. arbor The end of a circular saw shaft where the blade is mounted. auger bit A drill bit with a spiral cutting edge for boring holes in wood and other materials. carbide A very hard material made of carbon and one or more heavy metals. Commonly used in one type of saw blade. chuck A clamping device that holds an attachment; for example, the chuck of the drill holds the drill bit. chuck key A small T-shaped steel piece used to open and close the chuck on power drills. countersink A bit or drill used to set the head of a screw at or below the surface of the material. Direct Current (DC) an electric power supply where the current flows in one direction only. DC power is supplied by batteries and by transformer-rectifiers that change AC power to DC forstner bit a bit designed for use in wood or similar soft material. the design allows it to drill a flat-bottom blind hole in material. grit a granular, sand-like material used to make sandpaper and similar materials abrasive. Ground Fault Circuit Interrupter (GFCI) A circuit breaker designed to protect people from electric shock and to protect equipment from damage by interrupting the flow of electricity if a circuit fault occurs. Ground fault protection Protection against short circuits; a safety device cuts power off as soon as it senses any imbalance between incoming and outgoing current kerf The channel created by a saw blade passing through the material, which is equal to the width of the blade teeth. masonry bit A drill bit with a carbide tip designed to penetrate materials such as stone, brick, or concrete. reciprocating Moving backward and forward on a straight line. revolutions per minute (rpm) The rotational speed of a motor or shaft, based on the number of times it rotates. ring test A method of testing the condition of a grinding wheel. The wheel is mounted on a rod and tapped. A clear ring means the wheel is in good condition; a dull thud means the wheel is in poor condition and should be disposed of. shank The smooth part of a drill bit that fits into the chuck. trigger lock A small lever, switch, or part that can be used to activate a locking catch or spring to hold a power tool trigger in the operating mode without finger pressure.