Gibraltar 42209G Heavy Hex Jam Nut 1-8 Unc Alloy Steel

Product Description

The GIBRALTAR 42209G is a heavy hex jam nut threaded to a 1-8 UNC specification for use in high-load fastening applications. Manufactured from alloy steel with a black oxide finish, this jam nut provides corrosion resistance and a hardened surface suitable for demanding mechanical environments. It measures 1-5/8 inches across flats and 35/64 inches in height. The right-hand thread direction is standard for the majority of bolted assemblies. Plumbers, pipefitters, millwrights, and general maintenance technicians use heavy hex jam nuts to lock standard hex nuts in place or to secure threaded rod connections under vibration and load.

This jam nut is suited for use in heavy industrial, commercial, and mechanical service applications where a standard hex nut does not provide adequate bearing surface or locking resistance. The heavy hex profile delivers a wider flat-to-flat dimension compared to a standard hex nut, distributing clamping load across a larger contact area. Typical installation scenarios include threaded rod assemblies, structural connections, and equipment mounting applications requiring a secondary locking nut.

Key Features

• 1-8 UNC thread form for broad compatibility with imperial threaded fastener systems
• Alloy steel construction for elevated tensile strength compared to low-carbon alternatives
• Black oxide finish for moderate corrosion resistance and reduced light reflection
• Heavy hex profile at 1-5/8 inches across flats for increased wrench bearing surface
• Right-hand thread direction matches standard bolting convention
• Low-profile jam nut height at 35/64 inches for space-constrained locking applications

Compatibility

Designed for use with 1-inch diameter, 8 threads-per-inch UNC threaded fasteners in heavy hex jam nut applications. Verify thread class and bearing surface requirements before installation.

Installation Notes

Installation is performed with a standard heavy hex wrench or open-end wrench sized to 1-5/8 inches across flats. Power down or de-energize any associated equipment before servicing threaded connections in electrical or mechanical systems. Torque the primary nut to specification first, then back-torque the jam nut against it to lock the assembly. Do not use impact tools to set jam nuts in precision or structural applications without verifying the fastener grade and joint requirements.