Manufactured from High Speed Steel for chamfering holes in many materials including steel, stainless steel and aluminum, 4602 Union Butterfield 3-flute countersinks come in sizes with 60, 82, 90 and 100 degree angles to chamfer holes to accommodate fasteners with the corresponding head angles. With a reduced plain shank, large diameter countersinks can be held in standard holders and chucks. The bright finish prevents workpiece material from sticking to the cutting surfaces of the tool, ensuring clean and accurate results, whilst the 3-flute design reduces vibration and chatter providing a smooth chamfering operation.