AT HSS Countersinks

AT HSS countersinks are cutting tools used to create a countersink (conical seat) or chamfer on drilled holes, and they’re also commonly used for deburring sharp edges after drilling (application dependent; verify per listing). In machining and fabrication, countersinks help prepare holes for flat-head fasteners and improve part finish by removing burrs that can interfere with assembly or inspection. High-speed steel (HSS) countersinks are a popular choice for general-purpose shop use, especially when you need a balance of toughness and cutting performance across a range of materials (application dependent).