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

Product Description

The VALUE COLLECTION 31-NTU-37C is a heavy hex lock nut with a nylon insert locking style, designed for use in threaded fastening applications where vibration resistance and secure clamping are required. Manufactured from 18-8 stainless steel with a bright, uncoated finish, this nut offers good corrosion resistance in moderate environments. It carries a 3/8-16 UNC thread size with right-hand thread direction. The heavy hex profile provides greater wrench bearing surface than a standard hex nut, making it suitable for higher-torque fastening situations. Plumbers, pipefitters, HVAC technicians, and general mechanical contractors install these in equipment assemblies, pipe supports, and structural connections.

This lock nut is appropriate for residential and light commercial mechanical installations where a secure, reusable threaded connection is needed. The nylon insert grips the mating bolt thread to resist loosening caused by vibration or thermal cycling, making it a practical choice for HVAC equipment mounting, plumbing fixture anchoring, pump installations, and general trade fabrication work. Its stainless steel construction is well suited for damp or corrosive environments where carbon steel fasteners would be unsuitable.

Key Features

• Nylon insert locking style resists loosening under vibration and thermal cycling
• 18-8 stainless steel construction provides corrosion resistance in wet and moderate chemical environments
• Heavy hex profile offers increased wrench-bearing surface for higher-torque applications
• 3/8-16 UNC right-hand thread for compatibility with standard inch-series fasteners
• Bright, uncoated finish with no added plating or treatment
• 11/16 inch width across flats fits standard hex wrenches and sockets

Compatibility

Designed for use with 3/8-16 UNC inch-series threaded bolts and studs in standard fastening assemblies. Suitable as a direct replacement or new-installation lock nut wherever a 3/8-16 heavy hex nylon-insert lock nut in stainless steel is specified.

Installation Notes

Installation is performed by hand-threading the nut onto the mating bolt until the nylon insert engages, then tightening with a standard hex wrench or socket. Nylon insert lock nuts are generally rated for a limited number of reuse cycles — inspect the insert for deformation before reuse. Ensure the fastener and mating material are compatible with 18-8 stainless steel to avoid galvanic corrosion in mixed-metal assemblies. Follow applicable mechanical codes and equipment manufacturer torque guidelines for the specific application.