... Ring and Seat Ring Thrust Collar, Series AS, LS, GS, WS, ZS, TRA, TRB, TRC TRD.Series AS thrust collar is ... , Series AS collar shall play its full action.Series GS, WS, LS thrust collars are made of bearing steel with the ... outer surfaceof GS seat ring and the inner surface of WS shaft ring are ground. Series LS thrust collar is an ...