The Series 1404 Straight Male NPT x Female NPSM hydraulic adapters, constructed from durable carbon steel, are essential fittings designed for secure connections in hydraulic systems that transfer fluids and gases. Utilizing the National Pipe Taper (NPT) standard, these adapters feature tapered threads that create a reliable seal through thread deformation, ensuring a metal-to-metal connection when tightened. The nominal pipe size can be determined by measuring the thread diameter and subtracting 1/4". NPSM (National Pipe Straight Mechanical) adapters, on the other hand, feature straight threads and are designed for mechanical sealing with a flat face, making them compatible with NPT fittings but not interchangeable. Unlike NPTF (National Pipe Tapered Fuel) fittings, which also use tapered threads for sealing, NPSM fittings do not rely on thread deformation for sealing; instead, they depend on an O-ring or flat surface to create a leak-proof connection. These adapters are ideal for professionals seeking reliable and efficient hydraulic solutions in various applications while providing optimal performance and safety in fluid transfer.