EE WAS HELPING TO MAKE A BELT SPLICE, HIS CO-WORKER WAS POUNDING WITH PICK HAMMER, A PIECE OF METAL BROKE OFF HAMMER AND WENT INTO HIS HAND. CAUSE OF INJURY WAS USING WRONG TOOL. COMPLIANCE WI TH RULES/REGS NOT A FACTOR. PROTECTIVE EQUIP WASA FACTOR, MINER PROFIENCY A FACTOR, MINING EQUIP/SYSTEM WAS A FACTOR.