Product Description LDR 317 MCO-18 Galvanized Merchant Coupling, 1/8-Inch. Lead free construction. Steel couplings meet ASTM A866. Galvanizing meets ASTM A-154. Working pressure 300 psi at 150-Degree F. Threads meet ANSI B1.20.2. From the Manufacturer LDR 317 MCO-18 Galvanized Merchant Coupling, 1/8-Inch. Lead free construction. Steel couplings meet ASTM A866. Galvanizing meets ASTM A-154. Working pressure 300 psi at 150-Degree F. Threads meet ANSI B1.20.2.