... , so do Ultra High Strength Sucker Rod Coupling, using 4142 steel bar YUNSHENG produce API ... , so do Ultra High Strength Sucker Rod Coupling, using 4142 steel barCOMPANY PROFILEYantai Yunsheng Petroleum ... sucker rod couplings, including Spray Metal coupling, class T coupling, Sub OD coupling, with various spec. of Full size ... FLATSSIZEO.D.I.D.LengthWeightWrench Flat(L×W)SM ThicknessSM ALLOY5/8”38.1mm23 ...