EE WAS INSTALLING 12 FOOT ROOF BOLTS IN INTERSECTION. FIRST TWO SECTIONS OF BOLTS WERE PLACED IN HOLE AND BECAME WEDGED. WHEN HE REACHED FOR THE THIRD SECTION OF BOLT, TOP SECTIONS OF BOLT FEL L FROM HOLE STRIKING THE TIP OF HIS LEFT RING FINGER, CREATING A LACERATION THROUGH HIS GLOVE. HE RECEIVED STITCHES AND RETURNED TO WORK ON RESTRICTED DUTY.