All brad point drill bits are manufactured to strict bosch factory standards extremely sharp drill bits for precise tear free drilled holes precision ground with cbn grinding process and cubic crystalline boron nitride grinding disc into fully hardened material standard brad point drill bits for rapid drilling up to 30 mm diameter also with a cordless drill suitable for hard and soft wood laminated and non laminated chipboard plywood countersink can also be used as a depth stop 4 0 x