I usually prop my ball bearing 46's (like the OS 46 AX) for 12,500-13,000 rpm on the ground (thats usually an 11x5, 11x6, or a 12x4). When the prop unloads in a full throttle dive, it will approach the manufacturers rated rpm of 16,000. Do not prop it for that many rpms on the ground. There are those that like to prop for even lower RPMs to reduce prop noise.

Brad