A lock includes a handle, a hub, and a spindle rotatably mounted in the hub and coupled to the handle to turn therewith. A transmission member is fixed to the handle to turn therewith. The transmission member is mounted around and not rotatably engaged with the spindle. The transmission member is stopped by the hub after the handle has been turned through an angle, transmitting a torque from the handle to the hub via the transmission member. Thus, impact from the handle can be partly transmitted to the hub and then to a door on which the lock is mounted, instead of completely transmitted to the spindle. Damage to the spindle is, thus, avoided.