Includes 1/4", 3/8", 1/2", 5/8", and 3/4" sizes, this 5-piece High Speed Steel (HSS) Single Flute Countersink Set is optimized for clean, controlled cuts with minimal vibration—especially in soft materials like plastic and aluminum. Featuring an 82° cutting angle and a single flute design, these countersinks provide excellent chip clearance and are less likely to chatter at lower speeds. Ideal for use with hand drills and lower-powered machines, this set delivers smooth, professional results whether you're deburring, chamfering, or prepping holes for flathead screws.