Product Information Material: Zinc Plated Steel Female Thread: NPSM Male Thread: NPTF Select a Product Part NumberFemale Thread SizeMale Thread SizeWorking Pressure 1503-6-63/8"-183/8"-184000 PSI 1503-12-123/4"-143/4"-142500 PSI 1503-4-41/4"-181/4"-184500 PSI 1503-16-161"- 11-1/21"- 11-1/22000 PSI 1503-8-81/2"-141/2"-143000 PSI