Gibraltar Z9279 Structural Flat Washer 1 in Alloy Steel

Product Description

The GIBRALTAR Z9279 is a structural flat washer designed for heavy-duty fastening applications where load distribution and clamp integrity are critical. Built from alloy steel with a zinc yellow dichromate finish, this washer delivers corrosion resistance and surface hardness suitable for structural bolted connections. It carries a Rockwell hardness rating of C43 to C49, making it appropriate for high-load assemblies where standard hardware-grade washers would be inadequate. The inch-system dimensions are precise and consistent with structural fastener specifications. Licensed tradespeople working on structural steel, mechanical equipment mounting, and heavy equipment installation will find this washer compatible with their standard torque and assembly workflows.

This washer is sized for a 1-inch screw, with an inside diameter of 1-1/16 inches, an outside diameter of 2 inches, and a thickness of 1/4 inch. It is suited for structural bolting in commercial and industrial construction, equipment bases, machinery anchoring, and similar applications where a hardened load-distributing washer is specified. The zinc yellow dichromate finish provides a dual layer of protection against oxidation, making it appropriate for indoor structural applications and moderately controlled environments.

Key Features

• Alloy steel construction with Rockwell C43-C49 hardness for high-load structural use
• Zinc yellow dichromate finish for corrosion resistance
• 1-1/16 inch inside diameter fits 1-inch screw fasteners
• 2-inch outside diameter provides wide load distribution across bearing surfaces
• 1/4 inch thickness maintains rigidity under clamp load
• Inch-system dimensions for compatibility with standard structural fastener specifications

Compatibility

Designed as a structural flat washer for use with 1-inch screw fasteners in heavy-duty bolted assemblies requiring hardened, load-distributing hardware.

Installation Notes

Installation is typically performed by ironworkers, millwrights, or mechanical contractors following applicable structural fastener specifications. Always verify that the washer hardness and dimensions match the bolt grade and joint design requirements before assembly. Ensure mating surfaces are clean and free of debris to achieve consistent clamp load. Follow applicable structural codes and fastener manufacturer torque guidance for the bolt grade in use.