Armeg WWBNP20 20mm Nail Proof Wood Beaver, represents the next generation of wood bit design. With the quad-flute quad cutting head design, the WoodBeaver provides ultra-smooth balanced cutting action, rapid drilling action, extreme durability, exceptionally clean breakthrough, maximising holes per charge. Designed with all the benefits of the standard Wood Beaver, the new Nail Proof features a Bi-Metal cutting head for longer life when drilling in nail embedded wood. The stronger cutting head design allows the Wood Beaver to provide effective drilling even after nail strikes. High speed steel cutting head increases durability in tough materials for longer life. Robust profile of 4 precision ground cutting teeth provides extreme resistance to hard objects.