XIZONLIN 25mm Forstner Drill Bit - Tungsten Carbide Woodworking Hinge Hole Cutter with Depth Stop (Hole Depth 10-40mm) - - Amazon.com
KWB Powerbox wood and Forstner drill set 5, 6, 15, 20, 25, 30, 35, 40 mm diameter 706078 (set of 8 pieces forged drill bits in accordance with ISO 7483 G) - - Amazon.com
FREUD PB-015 Precision Shear Forstner Drill Bit, 2" by 3-1/2", Multi - Jobber Drill Bits - Amazon.com