These HSS drill/countersinks drill the ANSI-specified clearance hole and an 82° countersink in hardwood, plastic, brass or other non-ferrous metals.
The center pilot is sized for the correct shaft clearance. Ideal for fast countersinking in wood, and dressing or resizing holes in hardware.
Each size will also countersink for one size lower (e.g., #4 will do both #3 and #4 screws). Shanked to size from 0.3125" to 0.500". Sold individually, or as a set of the three smaller sizes. A super buy.