The basic hub and blade retention is common to all models described. A hydraulic cylinder is mounted on the rotational axis connected to the blade clamps for pitch actuation. Blade clamps connect the blade shanks with blade retention bearings. The steel hub contains a central “spider,” that supports aluminum blades with a tube extending inside the blade roots. These propellers may be the nonfeathering type, or they may be capable of feathering and reversing. Many types of light aircraft use governor-regulated, constant-speed propellers in two-bladed and up to six-bladed versions. Most of the Hartzell propeller aluminum and steel hub models use centrifugal force acting on blade counterweights to increase blade pitch and governor oil pressure for low pitch. This is an exception to most of the aluminum hub models and feathering models. The centrifugal twisting moment of the blades tends to move them into low pitch (high rpm) in the absence of governor oil pressure. One model of nonfeathering aluminum hub constant-speed propeller utilizes oil pressure from a governor to move the blades into high pitch (reduced rpm). The propeller can be installed only on engines with flanged mounting provisions. The hydraulic cylinder, which provides power for changing the pitch, is mounted at the front of the hub. This hub shell carries the pitch change mechanism and blade roots internally. The hub shell is made in two halves, bolted together along the plane of rotation. In order to achieve these ends, the hub is made as compact as possible, utilizing aluminum alloy forgings for most of the parts. They combine low weight and simplicity in design and rugged construction. Hartzell compact aluminum propellers represent new concepts in basic design. Hartzell propellers can be divided by Aluminum hub (compact) and steel hub.

Mount and blade force single threading