Midland Industries 63702 Hex Locknut 3/8 Inch 316 Ss

Product Description

The MIDLAND INDUSTRIES 63702 is a 3/8-inch hex locknut machined from 316 stainless steel for use in threaded pipe systems requiring corrosion resistance and secure joint retention. Rated at 150 psi, this locknut features a 3/8-18 NPT female straight thread and is designed to lock a threaded fitting or nipple in place, preventing loosening caused by vibration or thermal cycling. Licensed plumbers and pipefitters install this type of fitting in industrial, commercial, and marine piping systems where standard carbon steel hardware is unsuitable due to exposure to moisture, chemicals, or corrosive environments.

This locknut is suited for 150-pound class threaded pipe assemblies in water, gas, and process piping applications. Its 316 stainless steel construction provides enhanced resistance to chlorides and acidic media compared to 304 SS, making it a practical choice for coastal installations, chemical plants, food service environments, and offshore applications. It is compatible with standard NPT threaded pipe and fittings in residential, commercial, and light industrial service.

Key Features

• 316 stainless steel construction for superior corrosion resistance in harsh or chloride-rich environments
• 3/8-18 NPT female straight thread for compatibility with standard pipe threads
• 150 psi pressure rating appropriate for 150-pound class piping systems
• Hex configuration allows installation with standard pipe wrenches or open-end wrenches
• Locks threaded fittings securely against vibration and thermal movement

Compatibility

Designed as a 150-pound class replacement locknut for 3/8-inch NPT threaded pipe systems using 316 stainless steel fittings.

Installation Notes

Installation is performed by licensed plumbers or pipefitters following applicable IPC and IFGC codes for threaded piping systems. Shut off and depressurize the piping system fully before removing or installing any threaded fittings. Apply appropriate thread sealant or PTFE tape to NPT threads before assembly. Do not overtighten; hand-snug plus one to two turns with a wrench is typical practice for NPT locknuts, and final torque should follow the system designer or fitting manufacturer guidelines.