M5 x 0.8 Left Hand Thread Milling Tap and Round Die and 4.2mm Drill Bit Set | eBay
4.2 mm Dia. x 6 mm Shank x 24 mm Flute Length x 66 mm OAL, 3xD, TiAlCN, 2 Flute, Coolant Thru, h6, Cylindrical, Solid Carbide Drill Series/List #NG11 MU061125688 - First Industrial Supplies