Bosch 84603M 23/32-Inch Plywood Mortising Router Bit
Carbide tipped plywood mortising bits are micrograin bits designed with undersized cut diameters to match up to the actual thickness of 1/4", 1/2" or 3/4" plywood. They produce a tight fit when mortising standard plywood.  84603M is for 3/4″ plywood.