UCAN carbide hammer drill bits are manufactured from the highest quality materials and are carefully checked at each production stage to ensure compliance with specifications. Correct drill sizing is extremely important because the performance of many types of concrete anchors can be adversely affected by inaccurate hole diameters. All UCAN inch drill sizes are made to strict ANSI (B 212.15 - 94) specifications. Metric sizes adhere to DIN (8035).