Gibraltar Z8848 M8 Extra Thick Flat Washer Case Hardened Steel

Product Description

The GIBRALTAR Z8848 is an extra thick flat washer designed for M8 screw applications requiring added load distribution and surface protection. Manufactured from case-hardened 1010 steel with a black oxide finish, this washer provides increased hardness at the contact surface while the black oxide coating offers mild corrosion resistance and a clean, low-reflectance appearance. At 5mm thick, it delivers substantially more bearing surface than standard flat washers, making it suited for assemblies where fastener pull-through or surface marring is a concern. Installation is straightforward for any mechanic, millwright, or maintenance technician working with M8 metric fasteners.

This washer is used in mechanical assemblies, structural connections, and equipment fabrication where metric fasteners are specified. The extra thickness suits applications involving softer base materials, oversized clearance holes, or high-clamp-load joints. It is commonly used in HVAC equipment assembly, electrical enclosure mounting, and general industrial maintenance. The black oxide finish is compatible with both indoor and lightly controlled outdoor environments when used with appropriate thread lubricants or sealants.

Key Features

• Extra thick at 5mm, well above standard flat washer dimensions for improved load distribution
• Case-hardened 1010 steel construction resists deformation under high clamp loads
• Black oxide finish provides mild corrosion resistance and low-reflectance appearance
• M8 screw size with 8.4mm inside diameter for proper metric fastener fitment
• 22mm outside diameter spreads bearing load across a wider surface area
• Metric dimensioning suits equipment built to ISO and DIN fastener standards

Compatibility

Designed for use with M8 metric screws and bolts in assemblies requiring an extra thick flat washer with a black oxide finish.

Installation Notes

Install using standard hand tools; ensure the washer seating surface is clean and free of burrs before assembly. Power down or de-energize any equipment before accessing fastened panels or assemblies. Follow applicable mechanical and structural codes for torque sequencing on critical joints. Do not substitute this washer in applications requiring hardened washers to a specific grade standard without verifying the material grade meets the design requirement.