12 Parts for agricultural and industrial tractors, bulldozers, loaders, excavators, pavers, trenchers, harvesters, feller-bunchers, compact track loaders, drillers, pipelayers, tile plows, and material handlers, namely, track group assemblies and parts thereof, namely, track chains, track links, track pins, track bushings, track grouser shoes, rubber shoes, rubber tracks, master links, thrust rings, track bolts, track nuts, and master link bolts; track rollers and parts therefor, namely, single flange shells, double flange shells, carrier roller shells, roller shafts, collars, roller bushings, and retainers; sprocket hubs, sprockets, and sprocket rims; idler assemblies and parts therefor, namely, idler shells, idler shafts, idler bushings, idler bearings and brackets; trunnions, seats, cushions for vehicle seats, arm rests, buckets, bucket teeth, adapters, end bits, wear buttons, protectors, elements, cutting edges, retainers and grouser retread bars, adapters in the nature of rings provided with bolt holes for use with sprockets to accept sprocket segment groups, segment bolts, segments nuts, segment sprocket nuts, sprocket segment groups in the nature of sprocket sections which when bolted together comprise the sprocket teeth