Gibraltar Z9090-SS Extra Thick Flat Washer 3/8 in Ss

Product Description

The GIBRALTAR Z9090-SS is an extra thick flat washer designed for use with 3/8 inch fasteners in demanding trade applications. Manufactured from Grade 18-8 stainless steel, it delivers strong corrosion resistance in wet, humid, or chemically active environments. The washer measures 7/16 inch inside diameter, 7/8 inch outside diameter, and 3/16 inch thick — noticeably heavier stock than standard flat washers. That additional thickness distributes load more effectively under bolt heads and nuts, reducing surface damage and fastener pull-through in softer substrates. Plumbers, HVAC techs, and electricians reach for this washer when standard-thickness hardware is not adequate for the joint or code requirement.

This washer suits a wide range of trade installations: pipe hangers, equipment mounting, structural connections, and any bolted assembly where corrosion resistance and load distribution are priorities. It is appropriate for both residential and light commercial work. The 18-8 stainless steel grade is well suited for indoor mechanical rooms, rooftop equipment mounts, and exterior applications where zinc-plated hardware would corrode prematurely. Sold individually, making it easy to source as a single replacement or in small quantities for service calls.

Key Features

• Extra thick construction at 3/16 inch provides superior load distribution versus standard flat washers
• Grade 18-8 stainless steel resists corrosion in wet and outdoor environments
• Fits 3/8 inch screw size with 7/16 inch inside diameter and 7/8 inch outside diameter
• Inch measurement system for straightforward compatibility with standard US fasteners
• Lightweight at 0.02 pounds, minimal impact on shipping weight when ordering multiples

Compatibility

Designed as an OEM-style replacement or service part for any assembly requiring a 3/8 inch screw-size extra thick flat washer in stainless steel per inch-standard fastener specifications.

Installation Notes

Installation requires no special tools beyond standard wrenches or nut drivers appropriate to the fastener being used. Always de-energize electrical equipment and shut off fluid systems before servicing any bolted connections. Stainless steel fasteners and washers can gall under high torque — use anti-seize compound where applicable and follow fastener manufacturer torque guidance for the specific bolt grade and size. Refer to applicable codes such as the NEC or IPC for fastener material requirements in specific trade applications.