Dead Centre

In a reciprocating engine, the dead centre is the position of a piston in which it is either farthest from, or nearest to, the crankshaft. The former is known as top dead centre (TDC) while the latter is known as bottom dead centre (BDC).A dead center (one that does not turn freely, i.e., dead) may be used to support the workpiece at either the fixed or rotating end of the machine. When used in the fixed position, a dead center produces friction between the workpiece and center, due to the rotation of the workpiece.Dead Centre refers to the position of a Piston when it is either farthest from or nearest to the Crankshaft. There are two types of Dead Centre: Top and Bottom. Top DC is where the Piston is farthest away, while Bottom DC is where it is closest. (Automotive engineering: Vehicle components, Engine, transmission, and exhaust) Top dead center is the position of an engine's piston when it is at the very top of its stroke.