600 longer life and higher cutting speeds compared with conventional spiral auger bits for precise highly accurate splinter free holes in veneered plywood as well as all natural hard soft and end grain woods specially milled spiral profile with screw point and lead in cutters design for centred cutting action with 10mm hexagonal shaft6 piece set 6 8 10 12 16 20x230mm in wooden storage case8 piece set 10 12 14 16 18 20 22 24x460mm in wooden storage case