THE CREW WAS PREPARING TO PUT CORE CASING IN A PREVIOUSLY DRILLED HOLE. JUST AS THE FIRST JOINT OF CASING WAS BEING HOISTED INTO PLACE THE INJURED WORKER PUT HIS HAND ON THE CLAMP HOLDING THE PIPE HIS MIDDLE R FINGER BECAME STUCK BETWEEN THE CLAMP AND LIFTING HOOK. THE TIP OF THE FINGER WAS PINCHED AND SEPARATED FROM THE HAND.