Gibraltar Z9163 Extra Thick Flat Washer 3/8 in 18-8 Ss

Product Description

The GIBRALTAR Z9163 is an extra thick flat washer designed for 3/8 inch screw applications requiring added load distribution and clamping depth. Constructed from 18-8 stainless steel with a plain finish, this washer resists corrosion in moisture-prone and chemically active environments. The extra thick profile — at 3/32 inch thickness — provides greater bearing surface rigidity compared to standard flat washers, making it well suited for fastener assemblies where deflection or embedment under load is a concern. Plumbers, HVAC technicians, electricians, and general contractors routinely use this washer type when securing equipment, hangers, and structural connections that demand durability over the service life of the installation.

This washer is appropriate for both residential and light commercial fastening applications. It is commonly used in HVAC equipment mounting, pipe hanger assemblies, electrical panel and fixture installations, and general mechanical connections where a 3/8 inch fastener is specified. The 18-8 stainless steel construction makes it a practical choice for outdoor, damp, or corrosive service environments where carbon steel hardware would degrade prematurely.

Key Features

• Extra thick profile at 3/32 inch (0.0938 inch) for enhanced load bearing and reduced fastener embedment
• 18-8 stainless steel construction provides corrosion resistance in wet and chemically active environments
• Plain finish — no coating to flake, crack, or interfere with electrical or mechanical contact surfaces
• Inside diameter of 13/32 inch (0.4063 inch) fits 3/8 inch screw shanks with standard clearance
• Outside diameter of 3/4 inch (0.7500 inch) distributes clamp load across a wider bearing surface
• Hardness rated Rockwell C36-C42 for consistent performance under mechanical loading

Compatibility

Designed as a standard replacement or supplemental flat washer for 3/8 inch fastener assemblies in trade and mechanical installations requiring extra thick stainless steel hardware.

Installation Notes

Install using standard hand tools appropriate for the fastener type. Ensure mating surfaces are clean and free of debris before seating the washer. For electrical installations, verify that hardware selection complies with applicable NEC requirements. Do not mix stainless steel fasteners with dissimilar metals in environments where galvanic corrosion could compromise the connection.