Gibraltar Z9280 Structural Flat Washer 1-1/8 in Alloy Steel

Product Description

The GIBRALTAR Z9280 is a structural flat washer designed for heavy-duty fastening applications requiring load distribution and clamping force under high-tension bolted connections. Manufactured from alloy steel with a zinc yellow dichromate finish, this washer provides corrosion resistance while meeting the hardness demands of structural assemblies. It is sized for a 1-1/8 inch screw, with an inside diameter of 1-3/16 inches, an outside diameter of 2-1/4 inches, and a thickness of 1/4 inch. The Rockwell C43-C49 hardness rating makes it suitable for structural bolting where softer washers would deform under load. Installers in structural steel, mechanical, and industrial trades rely on this washer where code-compliant joint integrity is required.

This washer is used in structural bolted connections across commercial and industrial construction, steel fabrication, heavy equipment assembly, and mechanical installations. Its alloy steel construction and dichromate finish make it appropriate for both indoor and outdoor environments where moderate corrosion resistance is needed alongside high hardness. It suits applications where ASTM or similar structural fastener standards call for hardened washers under bolt heads or nuts.

Key Features

• Alloy steel construction with Rockwell C43-C49 hardness for structural bolting loads
• Zinc yellow dichromate finish provides corrosion resistance
• Inside diameter of 1-3/16 inches fits 1-1/8 inch screw size with proper clearance
• Outside diameter of 2-1/4 inches distributes clamping load over a wide bearing surface
• Thickness of 1/4 inch provides rigidity under high-tension fastening
• Inch measurement system for compatibility with standard SAE fastener hardware

Compatibility

Designed as a structural flat washer for 1-1/8 inch screw or bolt sizes in heavy-duty mechanical and structural bolting applications.

Installation Notes

Structural flat washers are installed by ironworkers, millwrights, and mechanical contractors working on bolted steel connections. Place the washer under the bolt head or nut before torquing to the specified fastener requirement. Follow applicable structural codes and fastener manufacturer torque specifications for the bolt grade in use. Inspect the washer for deformation or finish damage before installation in corrosive or outdoor environments.