Value Collection 31-NU-37C Heavy Hex Lock Nut 3/8-16

Product Description

The VALUE COLLECTION 31-NU-37C is a heavy hex lock nut with a nylon insert locking mechanism, designed to resist loosening under vibration and dynamic loading. Manufactured from grade 18-8 stainless steel with a bright, uncoated finish, this fastener offers reliable corrosion resistance in wet, chemical-exposure, and outdoor environments. The 3/8-16 UNC thread size and right-hand thread direction make it a standard fit across a wide range of mechanical and structural assemblies. At 35/64 inches high with a width across flats of 39/64 inches, the heavy hex profile provides increased bearing surface compared to standard hex nuts. Licensed tradespeople and maintenance professionals working on HVAC equipment, piping systems, and electrical enclosures commonly specify this fastener type.

This lock nut is suited for use in residential and commercial applications where vibration resistance and corrosion-resistant hardware are required. Typical installations include HVAC equipment mounting, plumbing fixture assemblies, pump and motor mounting, and general mechanical service work. The nylon insert grips the mating thread without damaging it, making it appropriate for assemblies that may require periodic disassembly. The bright, uncoated surface keeps the stainless material visible for easy identification during installation.

Key Features

• Nylon insert locking style resists loosening from vibration without thread damage
• Grade 18-8 stainless steel construction for corrosion resistance in wet and outdoor environments
• 3/8-16 UNC right-hand thread for compatibility with standard inch-series fastener systems
• Heavy hex profile with 39/64 inch width across flats provides increased wrenching surface
• Bright, uncoated finish maintains base material appearance and dimensional accuracy
• Sold individually with a minimum order quantity of 5 units

Compatibility

Designed as an OEM-style replacement or service fastener for assemblies using 3/8-16 UNC inch-series threaded hardware requiring a heavy hex nylon insert lock nut.

Installation Notes

Installation is performed by hand-starting the nut onto a clean, undamaged 3/8-16 UNC male thread, then torquing with an appropriate wrench to the fastener manufacturer or equipment OEM specification. Ensure mating threads are free of debris and corrosion before installation. Nylon insert lock nuts are generally considered single-use; inspect the nylon insert for wear or deformation before reusing a removed nut. Follow applicable mechanical codes and equipment service manuals for proper torque requirements.