CONDUIT, METAL, RIGID, AND INTERMEDIATE; AND COUPLING, ELBOW, AND NIPPLE, ELECTRICAL CONDUIT: STEEL, ZINC COATED (S/S BY UL6A-ED1 AND UL514D-ED1) (SUPERSEDING WW-C-581D)
刚性和中间金属导管；以及电气导管接头、弯头和接头:镀锌钢（S/S由UL6A-ED1和UL514D-ED1提供）（取代WW-C-581D）

1977-04-06