Gasket is a mechanical seal between two objects, usually in order to prevent the pressure between two objects, corrosion, leakage and piping heat bilges cold shrink naturally. Due to mechanical processing surface can't be perfect, use the gasket to fill the irregularity. Gasket is usually made of sheet materials such as paper, rubber, silicone rubber, metal, cork, felt, neoprene, nitrile rubber, glass fiber or plastic polymers, such as PTFE). Application-specific gasket may contain asbestos.

Washers is a thin, usually circular, one of the holes (usually in the middle) is usually used to assign load thread fasteners. Other purposes as interval, springs, wear pads, display device, locking device. Rubber gasket is also used in the tap (valve) to cut off the flow of liquid or gas. Rubber or silicon gasket can be used, in order to reduce the vibration of the fan. Usually gasket diameter is around twice the diameter.