Gibraltar Z9161 Extra Thick Flat Washer 1/4 in 18-8 Ss

Product Description

The GIBRALTAR Z9161 is an extra thick flat washer designed for 1/4 inch screw applications. Manufactured from 18-8 stainless steel with a plain finish, it delivers corrosion resistance suitable for both indoor and outdoor installations. The extra thick profile — 0.0781 inches — provides increased load distribution compared to standard flat washers, reducing the risk of fastener pull-through in softer or thinner base materials. The inside diameter measures 0.2813 inches and the outside diameter measures 0.5000 inches. Licensed tradespeople and maintenance professionals installing fastener assemblies in plumbing, HVAC, electrical, or general mechanical applications will find this washer meets common dimensional requirements for 1/4 inch hardware.

This washer is suited for use wherever a 1/4 inch fastener requires a wider bearing surface or greater thickness than a standard flat washer provides. Common applications include panel mounting, equipment anchoring, pipe support bracketing, and structural fastening in corrosive or high-moisture environments. The 18-8 stainless steel construction makes it appropriate for use in wet locations, coastal environments, and installations where galvanic compatibility with stainless fasteners is a priority. It is sold individually with a minimum order quantity of 5 units.

Key Features

• Extra thick profile at 0.0781 inches for enhanced load distribution and pull-through resistance
• 18-8 stainless steel construction provides corrosion and oxidation resistance
• Plain finish — no coating to interfere with torque values or galvanic compatibility
• Inside diameter of 0.2813 inches fits standard 1/4 inch fasteners with appropriate clearance
• Rockwell hardness C36 to C42 for consistent performance under clamping loads
• Inch measurement system; outside diameter 0.5000 inches for broad bearing surface coverage

Compatibility

Designed as a standard-fit replacement or supplemental washer for 1/4 inch screw and bolt assemblies requiring an extra thick flat washer in stainless steel.

Installation Notes

Install using hand tools appropriate for the fastener type; ensure the washer seats flat against the bearing surface before final torque is applied. Power down or de-energize any equipment before servicing fastener assemblies in electrical or HVAC panels. Stainless steel hardware should be paired with stainless fasteners where possible to minimize galvanic corrosion. Follow applicable codes — NEC, IPC, or IFGC as relevant — for fastener requirements in trade installations.