2030AR Series Taper-Lok drills and reamers also known as Taper Lock Cutters, are manufactured to the most stringent tolerances for precision hole preparation. Spiral flute, Taper-Lok cutters drill, ream and countersink in a single operation. The AR series produce a countersink hole. Taper-Lok drills and reamers are manufactured to the most stringent tolerances for precision hole preparation. Standard in M-42 Cobalt.