This SAE Standard describes a uniform method to calculate and specify swing performance characteristics of material handlers, knuckle boom log loaders, delimbers, feller bunchers, harvesters processors, and other knuckle boom material handlers. It establishes definitions and specifies machining conditions for calculations and tests. This document applies to knuckle boom log loaders as defined in SAE J1209 and SAE J2055 and to certain forestry equipment defined in SAE J1209 and ISO 6814 that have rotating upper-structures such as feller bunchers, harvesters, processors, and forwarders. Included in the definition of knuckle boom log loaders are behind the car and rear-mounted log loaders not having their own power supply.The purpose of this SAE Standard is to establish a consistent, repeatable means of determining and specifying the swing performance for the types of equipment contained therein.