Parker 6-3/8 F5OF-S Pipe Adapter 9/16-18 X 3/8 Nptf

Product Description

The PARKER 6-3/8 F5OF-S is a straight industrial pipe adapter designed to connect male straight thread O-ring (SAE/UN) ports to male NPTF tapered pipe threads. Built from zinc-plated steel, it handles a maximum working pressure of 6,000 psi, making it suitable for high-pressure hydraulic lines and industrial fluid systems. The straight configuration allows a direct in-line connection with no angular offset. This adapter is sized for a 9/16-18 male straight thread O-ring end mating to a 3/8 male NPTF end. Hydraulic technicians and millwrights install this fitting when transitioning between SAE straight thread ports and NPT-style pipe connections in fluid power circuits.

This adapter is used in industrial hydraulic systems, mobile equipment fluid circuits, and high-pressure plumbing assemblies where a straight thread O-ring boss port needs to transition to a NPTF threaded connection. The 6,000 psi pressure rating supports demanding hydraulic applications in manufacturing, construction, and agricultural equipment. Its zinc-plated steel construction provides corrosion resistance in typical shop and field environments.

Key Features

• 6,000 psi maximum working pressure for high-pressure hydraulic service
• Male straight thread O-ring (UN/UNF-2A) to male NPTF straight configuration
• Zinc-plated steel construction for corrosion resistance
• 9/16-18 thread on one end, 3/8 NPTF on the other for direct port-to-pipe transition
• 11/16 inch hex size for standard wrench installation
• Overall length of 1-5/16 inches for compact in-line fitment

Compatibility

Designed for use in hydraulic and industrial fluid power systems requiring a transition from a male SAE straight thread O-ring boss port to a male NPTF pipe thread connection rated to 6,000 psi.

Installation Notes

Installation should be performed by a qualified hydraulic technician or pipefitter. Depressurize and isolate the hydraulic circuit completely before removing or installing any fittings. Apply appropriate thread sealant to the NPTF male threads per the system fluid compatibility requirements; the straight thread O-ring end seals via the O-ring and does not require sealant on the threads. Use a wrench on the hex flats only — do not grip the body — and avoid overtightening, which can damage the O-ring sealing surface or thread engagement.