washer

Washer is a term with several related meanings in everyday language and in technical contexts. It may refer to a clothes washing appliance, a small ring or disk used with fasteners, or a gasket used in plumbing.

A clothes washer, commonly called a washing machine, cleans garments by agitating or tumbling them in water combined with detergent. Most households use automatic machines that run through programmed cycles, adjusting wash time, water temperature, and spin speed. Front-loading and top-loading designs differ in mechanism and efficiency; front-loaders are generally more water- and energy-efficient but may have higher installation costs. In addition to basic washing, many machines offer specialized cycles for delicates, heavy soils, or quick washes. The development of high-efficiency washers and consumer guidance on energy use has influenced appliance labeling and consumer choice.

The hardware sense of a washer is a flat ring or disk placed under a bolt or nut to distribute load, prevent galling, or act as a spacer. Common types include flat washers, lock washers (which resist loosening), and spring washers (which provide preload or locking action). They are made from steel, stainless steel, brass, aluminum, rubber, or plastics and are used in machinery, construction, automotive, and electronics.

In plumbing, a washer is a gasket or seal situated between joints or fittings to prevent leaks. Materials range from rubber and elastomeric compounds to PTFE and fiber composites, chosen for compatibility with the fluid and temperature. They appear in faucets, compression fittings, flanges, and pipe joints.