A failsafe workholding clamping assembly includes a base, an axially slidable draw bar and collet, and a force amplifier. A driver applies a continuous driving force to the force amplifier. The force amplifier amplifies the driving force and applies a resulting amplified force to the draw bar to bias the draw bar toward its closed position and the collet toward its gripping position. A collet opener mounts to the base and selectively applies an opening force to the draw bar to counteract the driving force and move the collet into its released position. The workholding clamping assembly holds a collet in a predetermined rotational orientation and includes a draw bar rotating mechanism to enable an operator to rotate the draw bar to threadingly engage the draw bar and a rotationally-fixed collet.