Value Collection 31-NU-87C Heavy Hex Lock Nut 7/8-9 Ss

Product Description

The VALUE COLLECTION 31-NU-87C is a heavy hex lock nut with a nylon insert, designed to resist loosening under vibration and dynamic loads. It is threaded 7/8-9 UNC with a right-hand thread direction and manufactured from grade 18-8 stainless steel for corrosion resistance in wet, chemical-exposure, or outdoor environments. The nylon insert creates an interference fit that prevents the nut from backing off without the need for thread-locking compounds. At 1.125 inches tall with a 1.4375-inch width across flats, this is a heavy-series fastener suited for structural and mechanical assemblies where standard hex nuts are insufficient.

This nut is used in plumbing, HVAC equipment mounting, pool and water treatment hardware, and general industrial or trade applications where stainless steel fasteners are required. The 7/8-9 UNC thread size is common in medium-to-heavy structural connections. Trade professionals including pipefitters, mechanical contractors, and equipment installers use this fastener when securing flanges, equipment frames, pipe supports, and similar assemblies exposed to moisture or corrosive conditions.

Key Features

• Nylon insert locking style resists vibration-induced loosening without adhesives
• Grade 18-8 stainless steel construction offers corrosion resistance in wet and chemical environments
• Heavy hex profile provides greater bearing surface and wrench engagement than standard hex
• 7/8-9 UNC right-hand thread conforms to Unified National Coarse fastener standards
• 1.125-inch height and 1.4375-inch width across flats for high-torque applications

Compatibility

Designed as a standard UNC replacement or new-installation heavy hex lock nut for 7/8-9 threaded fastener applications in mechanical, HVAC, plumbing, and industrial assemblies.

Installation Notes

Installation should be performed by a qualified mechanic or trade professional using an appropriately sized wrench or socket matched to the 1.4375-inch across-flats dimension. Verify that mating threads are clean and free of damage before assembly. Because the nylon insert provides the locking function, the nut should not be reused after removal as the insert loses clamping effectiveness with repeated cycling. No thread-locking compounds are required or recommended with nylon insert lock nuts.