EMPLOYEE REPORTED: INSTALLING ROOF BOLTS IN A FACE AREA, AFTER DRILLING HOLE WHEN ATTEMPTING TO INSTALL THE ROOF BOLT IN THE DRILLED HOLE, THE BOLT CAUGHT IN THE HOLE AND BENT. WHEN ROTATING T HE BOLT TO ANCHOR, THE BELT BOLT STRUCK HIS LEFT THUMB. (STARTED MISSING SCHEDULED WORK DAYS ON 11-29-2003).