TJR® Countersink 90° Set of 6 Pieces 1/4", 1/3", 2/5", 1/2", 2/3", 4/5" HSS Uncoated, for chamfering. Tool Bits Set for Steel, Aluminum, Brass, Wood, Plastic (Uncoated in Original Rose Plastic Case)TJR Countersinks 90 set of 6 pcs for chamfering. High Speed Steel (HSS) Our countersinks are crafted from durable and heat resistant High Speed Steel (HSS) material. This ensures long lasting performance and exceptional durability even under demanding drilling conditions. These countersinks are suitable for a wide range of materials, including wood, plastic, and various metals. Unigue 3 Flute design Three flute design which enhances stability and