Machines and apparatus within this class for chipping, or comminuting wood and timber materials, as well as parts and accessories therefor; wood hoggers, and parts as well as accessories therefor; grinding and chipping discs, as well as parts and accessories therefor; replaceable teeth and tooth assemblies for apparatus for processing wood; sections of grinding or chipping discs; grapples including powered saw means; saws for use with grapples; grapples and lifting apparatus for logs; slides for use with grapples; powered beaters for use with wood hoggers or apparatus for comminuting or screening materials; hydraulic motors