Value Collection MP440005 Hex Lock Nut 3/8-16 Grade 2

Product Description

The VALUE COLLECTION MP440005 is a 3/8-16 hex lock nut with an expanding flex-top locking style, manufactured from Grade 2 steel with a cadmium finish. The expanding flex top provides resistance to vibration-induced loosening without requiring a separate nylon insert or chemical thread-locking compound. At 0.4620 inches in height and 0.5640 inches across the flats, this nut follows standard inch-series dimensions with a right-hand thread direction and a Thread Fit Class 2B designation. The cadmium finish provides corrosion resistance in moderate-exposure environments. This fastener meets MIL-S-7742 military specification requirements, making it suitable for applications where traceability to a fastener standard is required.

This nut is used in mechanical assemblies across HVAC, plumbing, electrical, and general industrial applications where a positive locking hex nut in the 3/8-16 thread size is specified. The flex-top expanding collar engages the mating thread under torque to resist loosening from vibration or thermal cycling. It is well suited for equipment panels, brackets, and structural fastening points in both residential and light commercial installations where Grade 2 steel meets the load requirements.

Key Features

• Expanding flex-top locking style resists vibration-induced loosening without inserts or adhesives
• 3/8-16 right-hand thread, Thread Fit Class 2B for standard inch-series mating hardware
• Grade 2 steel construction with cadmium finish for corrosion resistance
• Meets MIL-S-7742 military fastener specification
• Flange diameter of 0.5530 inches provides a bearing surface that helps distribute clamping load
• Width across flats 0.5640 inches; width across points 0.6310 inches — fits standard 9/16-inch hex tooling

Compatibility

Designed as a direct-fit replacement or service fastener for any 3/8-16 inch-series threaded application requiring a hex lock nut with an expanding flex-top locking feature per MIL-S-7742.

Installation Notes

Installation is performed with standard 9/16-inch hex tooling. Ensure the mating threaded fastener and joint surface are clean and free of debris before assembly. Power down or de-energize any equipment before fastener service work on electrical or HVAC components. Do not reuse expanded flex-top lock nuts that have been fully torqued, as repeated cycling can reduce locking effectiveness.