2030BR 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 (also known as Taper Locks) drill, ream and countersink in a single operation. The BR series are for protrusion head fasteners. Taper-Lok drills and reamers are manufactured to the most stringent tolerances for precision hole preparation. Standard in M-42 Cobalt.