- the position of maximum (top dead center) or minimum (bottom dead center) extension of a crank and a connecting rod, in which both are in the same straight line
- a nonrevolving center, as of a lathe spindle
- the exact center
The point at the end of each stroke of a moving crank and connecting rod at which the two lie in the same straight line and the turning force applied by the connecting rod is zero. Also called dead point.