Midland Industries 500066 Steel Pipe Coupling 3/8 Nptf

Product Description

The MIDLAND INDUSTRIES 500066 is a straight pipe coupling designed for hydraulic plumbing applications where two female NPTF threaded lines must be joined. Built from steel and rated to 3000 psi maximum operating pressure, this fitting handles demanding hydraulic system pressures with reliable thread sealing. Both ends accept 3/8-inch female NPTF connections with a 3/8-18 thread spec, and the coupling is rated for service up to 375 degrees F. It meets SAE 140138 dimension standards, ensuring consistent dimensional fit within compliant hydraulic assemblies. Plumbers, hydraulic technicians, and fluid power mechanics install this fitting in both mobile and stationary hydraulic systems.

This coupling is used in hydraulic lines where two female-threaded ports or hose ends need to be connected inline without directional change. The NPTF thread form provides a pressure-tight, metal-to-metal seal that reduces reliance on thread sealants in high-pressure hydraulic circuits. Typical applications include agricultural equipment, industrial machinery, and mobile hydraulic systems. The steel construction makes it appropriate for hydraulic oil, water-based fluid, and other compatible media in both residential-scale and light commercial hydraulic plumbing.

Key Features

• 3000 psi maximum operating pressure rating for high-demand hydraulic service
• Both ends: 3/8-inch female NPTF with 3/8-18 thread for pressure-tight metal-to-metal sealing
• Rated to 375 degrees F for elevated-temperature hydraulic fluid service
• Meets SAE 140138 dimensional standards for consistent component interchangeability
• Steel construction suited for hydraulic oil and compatible fluid media
• Compact profile: 1.1 inches height, 0.75 inches length, 0.85 inches width

Compatibility

Designed as an OEM-style steel hydraulic pipe coupling for hydraulic systems using 3/8-inch female NPTF threaded connections and operating within the rated pressure and temperature limits.

Installation Notes

Installation should be performed by a qualified hydraulic technician or licensed plumber. Depressurize and isolate the hydraulic circuit fully before removing or installing any fittings. Inspect threads for damage before assembly, and apply thread sealant only as required by system specifications and applicable standards. Torque to the system or fitting manufacturer guidelines found in the applicable hydraulic assembly documentation.