Annular Area
Definition
The effective piston area on the rod side of a hydraulic cylinder, calculated as A_annular = A_bore - A_rod. This area determines retract (pull) force and flow requirements for retraction.
Practical Note
Rod-to-bore ratio typically 0.5-0.7. Area ratio (bore/annular) of 2:1 means retract force is half of extend force, but retract speed is twice as fast at same flow rate.