Gibraltar Z8958H Square Flat Washer 3/4 in Bolt 2 in Square

Product Description

The GIBRALTAR Z8958H is a square flat washer engineered for 3/4 inch bolts and fabricated from case hardened steel with a black oxide finish. The washer measures 2 inches square and 1/4 inch thick, with an inside diameter of 13/16 inches. The black oxide coating provides corrosion resistance and reduces light reflection, making it suitable for both structural and general mechanical fastening applications. Licensed tradespeople in construction, plumbing, HVAC, and electrical work use this type of washer to distribute load across bolted connections and reduce fastener pull-through on structural members.

This square flat washer is suited for use in residential and commercial construction, mechanical equipment mounting, and structural fastening where a larger bearing surface than a standard round washer is required. The 2 inch square footprint distributes clamping force over a wider area, reducing stress concentration at the bolt hole. It is commonly installed by ironworkers, millwrights, plumbers, and HVAC technicians when securing equipment to structural steel or treated lumber.

Key Features

• Case hardened steel construction for high tensile strength and wear resistance
• Black oxide finish for corrosion resistance and low-glare appearance
• 2 inch square profile distributes load over a wider bearing surface than round washers
• 13/16 inch inside diameter sized for 3/4 inch bolts
• 1/4 inch thickness provides rigid support under fastener load

Compatibility

Designed for use with 3/4 inch bolts as an OEM-style or replacement square flat washer in structural, mechanical, and equipment-mounting applications.

Installation Notes

Install with standard hand tools and torque wrenches appropriate for 3/4 inch fastener assemblies. Ensure mating surfaces are clean and free of debris before seating the washer. Follow applicable building codes and mechanical standards for fastener torque requirements on structural connections. Do not substitute this washer in applications requiring a specific ASTM-rated washer unless confirmed compatible by a qualified engineer.