Guhring 8521-4.500 4.5mm DIN 6537L Ratiobohrer HF Signum Carbide Drill

This is a new Guhring Ratiobohrer HF Signum solid carbide twist drill, catalog number 8521-4.500, conforming to DIN 6537L (long series, through-coolant) with a right-hand cut (R) and RT1 point geometry. The drill features a 4.5 mm cutting diameter with a cylindrical shank of 16 mm diameter — a reduced-neck / stepped-shank configuration consistent with DIN 6537L long-series geometry — and is manufactured from ultrafine-grain carbide substrate. The "HF Signum" designation indicates Gühring's internal coolant channel design optimized for high-feed drilling in steel, cast iron, and stainless materials, with two helical coolant bores visible at the drill tip in the product photo. The RT1 point geometry features a 140° point angle with self-centering capabilities, eliminating the need for a pilot hole in many setups. This drill is designed for use in CNC machining centers with through-spindle coolant supply and is compatible with standard ER collet chucks or hydraulic toolholders accepting a 16 mm cylindrical shank.

Product Specifications