Mercury - CNC Outboard Cleaver 400 HP 15-Degree Racing Propeller - 5-Blade - 300R and 400R - 15.25 Dia. - 33 Pitch - 48-8M0148162. The Lab Finished CNC Outboard Cleaver is designed to be the most efficient propeller for high speed applications. As opposed to a standard propeller, the CNC machining process offers superior precision and replicability for all dimensions of the propeller.. 15-degree rake is applicable for lightweight or air entrapment hulls that do not require additional bow lift. Broched splines for 1.25 inch prop shaft, designed for 300R and 400R outboard models