The Series 5406-HP Hollow Hex Male NPTF Pipe Plugs are high-quality, durable fittings designed to seal unused NPTF (National Pipe Tapered Fuel) ports in hydraulic and fluid power systems. Made from carbon steel, these hollow hex male plugs feature NPTF threads, which create a secure, leak-free seal through metal-to-metal contact when tightened. The hollow hex design allows for easy installation and removal with standard wrenches, offering convenience during maintenance or testing. These plugs are ideal for preventing fluid leaks and contamination, ensuring system integrity in high-pressure environments. The Series 5406-HP plugs provide reliable and long-lasting performance for fluid transfer systems, making them an essential component for sealing ports during system assembly, maintenance, or testing.