Gibraltar 74213240 Round Knurled Check Nut 1-8 Unc Steel

Product Description

The GIBRALTAR 74213240 is a steel round knurled high torque check nut designed for secure, tool-friendly fastening in demanding industrial and mechanical applications. Manufactured from steel with a black oxide finish, this check nut features a knurled round head that provides an enhanced grip surface for hand tightening under high torque conditions. It is threaded to a 1-8 UNC specification with a 2 inch head diameter, a 1-3/4 inch base diameter, and a 9/16 inch overall height. The black oxide coating provides mild corrosion resistance and reduces light reflection. Machinists, millwrights, and maintenance technicians are the typical installers for this type of hardware.

This check nut is suited for use in machine tooling, fixture assemblies, jigs, and general industrial fastening applications where a locking nut with a grippable profile is required. The 1-8 UNC thread pitch is a coarse-thread standard common across a wide range of bolts, studs, and threaded rods in trade and industrial settings. It is appropriate for applications requiring repeated adjustment and re-locking without the need for a separate wrench on the nut body.

Key Features

• 1-8 UNC coarse thread for broad compatibility with standard threaded fasteners
• Round knurled head profile enables hand tightening and high torque application without a wrench
• Black oxide finish provides mild corrosion resistance and a low-glare surface
• 2 inch head diameter with 1-3/4 inch base diameter for a stable seating footprint
• Steel construction for durability in mechanical and industrial environments
• 9/16 inch overall height suits compact fastening arrangements

Compatibility

Designed as an OEM-style replacement or direct-fit check nut for standard 1-8 UNC threaded bolts, studs, and rods used in machine tool fixtures, jigs, and general industrial assemblies.

Installation Notes

Installation is typically performed by machinists, millwrights, or maintenance technicians using hand pressure or standard tools on the mating fastener. Ensure the mating thread is clean and free of debris before threading the nut to avoid cross-threading or damage to the UNC thread form. Verify thread engagement depth meets the requirements of the application before applying final torque. Follow applicable industry standards and equipment manufacturer guidelines for locking nut installation in your specific assembly.