EMPLOYEE WAS CLEANING OUT A SMALL FEED HOPPER FOR CO-WORKER, MILL #3. HE TOOK A SMALL DOOR OFF THE SIDE OF THE HOPPER AND USED HIS HAND TO CLEAN OUT A MATERIAL BLOCKAGE. HE PUSHED HIS HAND TOO FAL INTO THE HOPPER AND CUT THE TIP OF HIS MIDDLE FINGER ON THE SCREW IN THE BOTTOM OF THE FEED HOPPER. THE SKIN AT THE TIP OF HIS FINGER WAS CUT, THE FINGER NAIL WAS NOT CUT.