Gibraltar Z8806 Extra Thick Flat Washer M6 Black Oxide

Product Description

The GIBRALTAR Z8806 is an extra thick flat washer designed for M6 screw installations requiring increased load distribution and surface protection. Manufactured from case-hardened 1010 steel with a black oxide finish, this metric washer delivers improved hardness and corrosion resistance compared to standard soft-steel flat washers. The black oxide coating reduces surface friction and provides moderate rust inhibition in indoor and light-duty outdoor applications. With an inside diameter of 6.4 mm, an outside diameter of 13 mm, and a thickness of 2.5 mm, it meets the dimensional requirements for extra thick metric flat washers used in precision fastening assemblies. Maintenance technicians, millwrights, and field service professionals working with metric fastener systems will find this washer suited to bolted joint applications where standard thickness washers are insufficient.

This washer is used wherever M6 metric fasteners require a wider bearing surface or additional stack height under the fastener head or nut. Typical applications include equipment mounting, panel assembly, machine framing, and structural bolted connections across HVAC equipment, electrical enclosures, and general mechanical assemblies. The extra thick profile helps prevent fastener pull-through in softer base materials and maintains clamp load in vibration-prone assemblies. The black oxide finish makes it suitable for indoor environments and light-exposure installations where a non-reflective surface is preferred.

Key Features

• Extra thick 2.5 mm profile provides greater load distribution than standard flat washers
• Case-hardened 1010 steel construction resists deformation under high clamp loads
• Black oxide finish offers moderate corrosion resistance and a non-reflective surface
• 6.4 mm inside diameter fits M6 fasteners with proper running clearance
• 13 mm outside diameter widens bearing surface to reduce pull-through risk
• Metric dimensioning consistent with ISO fastener standards

Compatibility

Designed for use with M6 metric screws and bolts in bolted joint assemblies requiring an extra thick flat washer per metric fastener standards.

Installation Notes

Installation requires no special tooling beyond the wrench or driver used for the M6 fastener. Power down and de-energize any electrical or mechanical equipment before performing fastener service on live systems. Do not substitute this metric washer in imperial fastener applications where dimensional fit has not been confirmed. Inspect washers for burrs or deformation before installation to ensure proper seating and clamp load distribution.