Midland Industries 63701 Hex Locknut 1/4-18 316 Ss 150 Psi

Product Description

The MIDLAND INDUSTRIES 63701 is a 1/4-inch nominal hex locknut rated for 150 psi service in 316 stainless steel construction. It features a 1/4-18 thread with a female straight connection, making it a direct-fit component for securing pipe fittings and preventing loosening under pressure or vibration. The 316 stainless steel alloy provides strong resistance to corrosion and pitting, suitable for aggressive media and outdoor or wet environments. Plumbers, pipefitters, and mechanical contractors install this type of locknut when a threaded fitting assembly requires a positive mechanical lock against a panel, bulkhead, or mating fitting body.

This locknut is used in 150-pound pressure class piping assemblies across residential and light commercial applications. Typical installation scenarios include securing threaded pipe connections through panels, manifolds, or enclosures where vibration or movement could allow fittings to back off over time. The stainless steel material makes it a common choice for water treatment, chemical handling, food service, and marine-adjacent plumbing systems where carbon steel or brass may not be appropriate.

Key Features

• 316 stainless steel construction for superior corrosion resistance
• 1/4-18 female straight thread for standard NPT pipe system compatibility
• 150 psi pressure rating suitable for 150-pound class fitting assemblies
• Hex profile for wrench engagement during installation and removal
• Compact dimensions allow use in tight panel or bulkhead installations

Compatibility

Designed as an OEM-style replacement or new-installation component for 150-pound class threaded pipe fitting assemblies using 1/4-inch nominal NPT connections.

Installation Notes

Installation is typically performed by a licensed plumber or pipefitter following applicable IPC or mechanical code requirements for the jurisdiction. Shut off and depressurize the affected piping system before disassembling or installing any threaded fittings. Use an appropriately sized hex wrench or open-end wrench on the hex flats to avoid rounding. Apply thread sealant or PTFE tape as required by the system media and local code.