| A | B |
|---|
| grit | A granular abrasive used to make sandpaper or applied to the surface of a grinding wheel to give it a nonslip finish. Grit is graded according to its texture. The grit number indicates the number of abrasive granules in a standard size (per inch or per cm). The higher the grit number, the finer the abrasive material. |
| 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. |
| hazardous materials | Materials (such as chemicals) that must be transported, stored, applied, handled, and identified according to federal, state, or local regulations. Hazardous materials must be accompanied by material safety data sheets (MSDSs). |
| hydraulic tools | Tools powered by fluid pressure. The pressure is produced by hand pumps or electric pumps. |
| masonry | Building material, including stone, brick, or concrete block. |
| pneumatic tools | Air-powered tools. The power is produced by electric or fuel-powered compressors. |
| reciprocating | Moving back and forth |
| revolutions per minute (rpm) | The number of times (or rate) a motor component or accessory (drill bit) completes one full rotation every minute. |
| 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 you push or pull to activate a locking catch or spring. Activating the trigger lock causes the trigger to stay in the operating mode even without your finger on the trigger. |
