1)ISO9001:2008 quality management system 2) more than 20 years manufacturing experiences TCT Hole sawTCT hole sawhss hole sawdiamond hole sawmetal hole sawFeatures:1) Variable pitch teeth for faster, smoother cutting and less vibration2) Longer lasting design for more cuts per saw3) Long cutting life, for the builders, tile setters, home owners, do-it-ourselves,construction workers and other ...