Rta furniture step drill bit creates steps for the confirm at style furniture screw. Used for drilling pilot hole, clearance hole and Countersinking, #55292, (B) Cutting height: 19mm, (D) diameter: 5mm, (D) shank: 1/4, overall length (L): 62mm, B1: 5mm, D1: 7mm, D2: 10mm, D3: (10mm), L1: 38mm, 55292 RTA furniture drill/Countersink with Quick release 1/4 hex shank for 7mm screw