These must be the ultimate in Forstner cutters. Multi-directional, with diamond ground cutting edges to give the sharpest cleanest holes. The whole end of the Forstner is made from M2 high speed steel. Suitable for cross and end grain work it uses a lip and spur drill bit as the central point, this can be adjusted for length ensuring a positive drive even at angles. Fitted with the unique RotaStop shank that guarantees a positive lock in the chuck or extension bar and a quick release. The periphery of the hole is pre-cut before the main cutters commence work which prevents splintering. The main cutters are sectional to create smaller shavings which permits a higher drill feed speed and faster work. Running at the correct speed is very important, sizes to be run at the following speeds: 15 and 20mm run at 2,000-3,000rpm, 25-35mm run at 1500 - 2,500rpm, 36-45mm run at 1,200-1,800rpm and 46-55mm run at 800-1,200rpm. Bits are 10mm shank up to 40mm diameter and 13mm there after. Made in Germany. Extensions and a 2MT adaptor is available for use with these Forstner bits up to 40mm diameter cutters.