Roller capacity refers to the maximum static load a single roller can support in a conveyor system. Load capacities listed are always based on the between frame length of the conveyor roller, actual load ratings for the roller bearing, roller tube and shaft deflection. Load capacities for precision roller bearings allow for 3/4 of a degree of shaft deflection at the bearing. For commercial unground bearings it is 1 full degree. When selecting a roller for a specific material handling application, a good rule of thumb is to allow 30% more capacity than the heaviest product being conveyed. To ensure smooth conveyance of any and all products, factory engineers recommends that a minimum of 3 conveyor rollers be in contact with the conveyed product at all times.