Value Collection 831991MSC M8x1.25 K-lock Hex Nut

Product Description

The VALUE COLLECTION 831991MSC is an M8x1.25 zinc plated steel K-Lock hex nut with an integrated external tooth lock washer. This fastener combines a standard hex nut with a built-in serrated lock washer that bites into the mating surface under torque, resisting loosening from vibration and dynamic loads. The nut is manufactured from steel with a zinc plated finish for basic corrosion resistance. It is sized at M8 with a 1.25mm thread pitch, a 13mm width across flats, and a 15mm washer diameter. Electricians, HVAC technicians, plumbers, and general mechanical trades use this style of fastener wherever a self-locking one-piece assembly is required.

K-Lock hex nuts with external tooth lock washers are used in a wide range of light to medium-duty mechanical and electrical assembly applications. Common install scenarios include panel mounting, equipment enclosures, conduit fittings, motor mounts, and structural fastening where a separate loose lock washer is impractical. The external tooth design provides higher locking friction than a plain hex nut while eliminating the need to handle a separate washer component during assembly.

Key Features

• M8x1.25 thread size for compatibility with standard metric M8 fastener applications
• External tooth lock washer integrated into the nut for single-piece installation
• 13mm width across flats fits standard metric hex wrenches and sockets
• 15mm washer diameter provides a wider bearing surface than the nut body alone
• Zinc plated steel finish offers basic corrosion protection in dry or low-moisture environments

Compatibility

Designed as a standard metric M8x1.25 K-Lock hex nut suitable for use with any M8x1.25 threaded bolt or stud conforming to standard metric thread specifications.

Installation Notes

Installation is performed by hand-threading followed by tightening with a standard 13mm metric wrench or socket. Always ensure the mating bolt or stud threads are clean and free of debris before assembly. The external tooth lock washer requires direct metal-to-metal contact with the mating surface to function correctly — do not install over soft materials, coatings, or oversized clearance holes that would prevent the teeth from engaging. De-energize any electrical panel or equipment before fastening hardware in live enclosures in accordance with applicable NFPA 70 (NEC) requirements.