HSS / HSSE center drills 
60°, 90°, 120° with high positioning accuracy

Center drills for precise spot drilling of workpieces

Wandering, or deviation, of metal drills is a common problem when working with various materials. When a drill wanders during the drilling process, precision is compromised, potentially rendering the workpiece unusable depending on the extent of the deviation. To reduce production waste in industrial and workshop settings and to ensure consistently high precision in serial production, center drills are used. Unlike twist drills, which are intended to create the main hole, center drills are very short, making them less prone to wandering and allowing for a centered spot drill exactly at the designated point. This pre-drilling step ensures that the twist drill can be properly aligned in the next step, significantly reducing the risk of wandering during drilling. Center drills are also suited for other applications, such as supporting long workpieces using live centers or turning between centers. In all cases, precise and secure handling is a defining feature of quality center drilling tools.

Different types of center drills

A center hole consists of a cylindrical bore and a conical countersink, created by the specific shape of the cutting edges. Depending on the application, different shapes and types of center drills are available. Nachreiner offers high-quality HSS and HSSE center drills with tip angles of:

• 60 degrees
• 90 degrees
• 120 degrees

If you do not find the required drill size or tip angle in our selection, please reach out to us directly. We often provide custom tool solutions at reasonable prices to meet specific needs. As center drills do not have guide chamfers, they are unsuitable for deeper drilling. To avoid high lateral forces, center drills are therefore kept very short. They also feature a stepped profile that ends in the actual centering tip. The nominal diameter of center drills matches the diameter of the centering tip and typically ranges from 0.5 to 12.5 mm. The length of the centering tip usually exceeds the diameter by a few millimeters. Following the centering tip is the conical transition of the cutting edges, matching the chosen tip angle (either 60, 90, or 120 degrees) until they reach the shaft diameter. The relevant standards for center drilling tools are specified in DIN 333, while holes created with these tools comply with DIN 332.

Center drills should not be confused with NC spot drills, which are used on machine tools that offer high stability and geometric rigidity. NC spot drills operate without a centering tip, enabling shorter spot-drilling paths. Similar to center drills, NC spot drills are also unsuitable for deep holes, as they lack guide chamfers. Therefore, a twist drill is required to complete the hole after pre-drilling.