The Series 9643 Straight Female NPT x Female Metric Fixed adapters in carbon steel are fittings designed to connect systems with NPT (National Pipe Tapered) and metric threads. The NPT side uses tapered threads that form a secure, leak-proof seal by deforming the metal threads when tightened, making it ideal for fluid and gas transfer. The metric side, based on the DIN 7631 Series, features straight threads with a 60° cone on the male end, and a tapered nose on the female end. The seal is created when the male cone contacts the female tapered nose. These adapters are made from durable carbon steel, making them suitable for high-pressure applications where strength and reliability are crucial. They are not intended for frequent disassembly, and using a thread sealant is recommended to ensure optimal sealing performance.