ALL DIMENSIONS ABOVE ARE IN INCHES MODEL: Basic model sequence using the first 4 or 5 characters of your model. These numbers are for new propellers only! Older propellers may have slight variations. If purchasing a used propeller from someone, measure the specific propeller. THICKNESS: Propeller Hub Thickness BORE DIA: Center bore going through the propeller hub. LBORE DIA: Lightening Bore Diameter. Several Sensenich propellers have a larger opening on the camber (front / grey) side of the propeller. This is done to lighten the propeller's weight. We recommend avoiding a front spinner plate that pilots into the lightening bore due to chafing. BOLT DIA: Sensenich propellers currently come in three different bolt diameter sizes: 3/8, 7/16, and 1/2 inch based on the engine flange bushings or engine flange. As you can see, the propeller bolt holes are drilled slightly larger than the true bolt size. CB DIA: Counterbore Diameter. The counterbore dimension is for the thrust (rear / black) face of the propeller hub. These holes are drilled on the bolt hole center to accomodate the outside diameter of your flange bushings. If you are using a tapered shaft hub, you need to install A437 bushings into these counterbores. BC DIA: Bolt Circle Diameter. The bolt circle diameter is the diameter of the bolt pattern centered on the center of the hub with the diameter line crossing the center of the bolt hole. #: Number of bolt holes drilled into the propeller.
