The Adaptall Series 9325 Straight Male NPT x Female Metric Fixed rigid hydraulic adapters, made from carbon steel, are used to connect systems with different thread types: NPT and Metric. NPT (National Pipe Taper) fittings feature tapered threads that create a metal-to-metal seal, ideal for fluid and gas transfer in fixed, permanent connections. These fittings are designed for one-time assembly and are not suitable for frequent disassembly due to wear. The Metric side of the adapter is based on standards like ISO 9974, ISO 6149, and DIN 7631, which define metric threads commonly used in industrial and hydraulic systems. These Metric threads often resemble BSPP threads but with slight differences in pitch, chamfer angles, and sealing surfaces. It's important to carefully identify the correct type of Metric fitting to ensure compatibility and avoid leaks.