Miller Dowel joinery is a simple and revolutionary two-part system consisting of an engineered, stepped, hardwood dowel, and a matching stepped drill bit. Joints created with Miller Dowels combine the advantages of natural wood joinery with the ease of nails or screws. Superior fasteners for solid wood joinery. 40 Birch Dowels Size 2 included. 3 1/2in x 1/2in. Miller Step Drill Bit Required.