A tapered HSS drill is the gold standard for seating tapered screws such as traditional brass or silicon bronze screws in boatbuilding. These screws, which have some plain shank under the head, fully fill the drilled hole. The drilling depth is exactly adjustable to the borehole depth by means of an adjusting ring. The countersunk head is also adjustable in depth, so that a cover plug can be inserted if required. The drill flutes are generously dimensioned to eject shavings. Manufactured in Japan from wear-resistant HSS steel. Set 7-pieces: Ø 3.2 / 3.6 / 4.0 / 4.4 / 4.8 / 5.2 / 5.6 mm.