Gibraltar Z8954H Square Flat Washer 1/2 in Bolt Black Oxide

Product Description

The GIBRALTAR Z8954H is a square flat washer manufactured from case hardened steel with a black oxide finish. Designed for use with 1/2 inch bolts, it measures 2 inches square and 1/4 inch thick, with a 9/16 inch inside diameter. The case hardening provides improved load distribution and wear resistance under high-tension fastening applications. The black oxide finish offers a degree of corrosion resistance while reducing light reflection. This washer is used by electricians, plumbers, HVAC technicians, and general contractors wherever a larger bearing surface is needed to prevent bolt heads or nuts from pulling through a material.

This square flat washer is suited for structural fastening, equipment mounting, and utility installations in both residential and commercial settings. Its 2 inch square footprint spreads clamping load over a wider area than standard round washers, making it appropriate for softer base materials or oversized clearance holes. It is commonly used in mechanical, electrical, and plumbing panel installations, strut channel assemblies, and general trade work where bolt pull-through resistance is a requirement.

Key Features

• Case hardened steel construction for improved strength and wear resistance under load
• Black oxide finish for mild corrosion resistance and low-reflectance appearance
• 2 inch square footprint provides wider load distribution than standard round washers
• 9/16 inch inside diameter fits standard 1/2 inch bolt shank with clearance
• 1/4 inch thickness supports high-clamp-load applications

Compatibility

Designed for use with 1/2 inch bolts in general fastening, structural, and trade installation applications where a square bearing washer is specified.

Installation Notes

Installation requires standard hand or power tools for the corresponding bolt size. Ensure mating surfaces are clean and free of debris before seating the washer. Torque the fastener to the specification required by the assembly or applicable code. Black oxide finishes are not rated for immersion or highly corrosive environments without additional protective treatment.