Comparison : Item # 1317-36-172, M6 x 1.0 MPT Metric 90 Degree Angle Ball Check Grease Fitting Steel
Item # 1317-36-178, M8 x 1.0 MPT Metric 90 Degree Angle Ball Check Grease Fitting Steel
Item # 1317-36-184, M10 x 1.0 MPT Metric 90 Degree Angle Ball Check Grease Fitting Steel