Norseman 190-AQF Jobber Length Bully Premium drill bits with 3-Flat shanks. These heavy-duty 135° split point drills perform well in very demanding applications. The flats on the shank give positive chuck grip. The drills are ideal for use with hand held drills with keyless chucks, The heavy-duty construction and high molybdenum alloy steel make it ideal for hard metals, work hardening grades of stainless steel and other difficult to drill materials. The Ultra-Dex drill index is weatherproof, watertight, and unbreakable.