Pass-by - Deep Pocket, Mortise, Upcut, Spiral Router Bits - (3 Rough Flutes) Solid Carbide - Vortex 2373R. 1/2 Cutting Edge Diameter, 1 1/2 Cutting Edge Length, 1/2 Shank Diameter, 6 Overall Length, 4.5 Depth of Cut, 3 Finish Flutes. Pass-by router bits have a long overall length and a reduced diameter between the end of the cutting edge and the shank of the bit. This bit design is well suited for deep pocket mortise cuts and step cutting through thick materials. Now available in both roughing and finishing geometries. The roughing lock mortise bit provides fast material removal and is indicated with an R behind the part number.