Spray arm
The rotating perforated arm (usually one at the bottom and one under the top rack) that flings pressurized water onto your dishes during a wash cycle.
A dishwasher cleans with water, not soap alone — the **spray arms** are what turn the pump's pressure into the scrubbing jets that actually blast food off your plates. Each tiny hole is sized to aim a stream; when those holes clog with food bits, seeds, or **hard-water** scale, the arm's reach and pressure drop and dishes come out gritty or filmy, often only on the top rack. Spray arms usually pop off with a gentle pull or by unscrewing a center cap, so you can rinse them and clear each hole with a toothpick. Keeping them clear is one of the highest-impact fixes when a dishwasher stops cleaning well — see [why your dishwasher isn't cleaning](/guides/how-to-clean-and-maintain-your-dishwasher).