Challenge: To improve chip control when drilling long-chipping steels with a solid carbide tool.
Solution: A new drill geometry and carbide grade that significantly improves chip control, along with productivity and tool life.

A New Generation of Drills

Because the cutting action of a drill always takes place inside the workpiece, chip control (formation and evacuation of chips) is crucial for process security. Sandvik Coromant is launching an entirely new generation of solid carbide drills to minimize the inevitable compromise between security and performance in high-end drilling.

Intended particularly for the long-chipping and low-carbon steel machining (ISO P), the new drill tackles the problems previously encountered with chip control and excessive cutting forces.

During the development process, a large number of ideas and concepts were evaluated and simulated. The most promising ones were selected for prototyping and real-life tests. The prototypes were ranked according to key performance criteria such as chip control, noise level and cutting forces. Hole quality was evaluated in terms of dimensional, position and geometry tolerances and burr formation at the exit.

The best design, essentially a unique new geometry, was finally selected. The new cutting-edge shape and effective clearance offer low cutting forces, improved chip control and a higher penetration rate.

The redesigned rounding of the cutting edge and the corners of the drill tip lessens the risk of edge chipping and improves the coating adhesion. All this further improves process security.

CoroDrill® 860 will be available March 2012.

Originally published in Metalworking World 3.2011, a business magazine published by Sandvik Coromant.

Text: Turkka Kulmala