Maintenance tech. was in the process of replacing an air cannon @ the #2 gate east side. M1 had a ratchet in left hand and a 15/16 wrench in their right. The ratchet slipped off the bolt and struck M1 on the bottom lip. M1 immediately reported to the supervisor & went to the first aid clinic. M1 was carried to an offsite medical facility and received three dissolving sutures.