WHILE PUSHING A ROOF BOLT INTO THE ROOF IN A FALL AREA, USING A LONG BOLT TIGHTENING WRENCH THE OPERATOR WAS SPINNING THE BOLT TO MIX THE RESIN WHEN THE WRENCH CAME OFF THE HEAD OF THE BOLT AN D STARTED TO FALL WITH A CIRCULAR MOTION. THE OPERATOR STUCK HIS LEFT HAND OUT FOR PROTECTION AND THE STEEL HIT HIS HAND