Timberline 620-350 Hinge Boring 35-mm Diameter by 10-mm Shank and 2-Wing with Spurs, Carbide Tipped Boring Bit For European Style Concealed Hinges 35mm Cutting Diameter 10mm Shank, 57mm Length, 2-Wing With Spurs Unit Pack: Individually Carded Carbide Tipped, Professional Quality