Gibraltar 42621G Standard Flat Washer 3/8 in Case Hardened

Product Description

The GIBRALTAR 42621G is a standard flat washer designed for 3/8 inch screw applications. It is manufactured from case-hardened 1010 steel with a black oxide finish, providing improved surface hardness and corrosion resistance compared to plain steel washers. The washer measures 13/32 inches inside diameter, 7/8 inches outside diameter, and 3/16 inches thick. It is a general-purpose fastening component used by tradespeople, contractors, and maintenance technicians wherever load distribution and surface protection under a fastener head or nut are required.

This flat washer is suited for residential and commercial construction, mechanical assembly, HVAC equipment installation, electrical panel work, and plumbing fixture mounting. The inch-system dimensions make it a direct fit for standard 3/8 inch fastener hardware used in everyday structural and equipment-mounting applications. The black oxide finish is appropriate for interior use and lightly controlled environments where minor moisture exposure is possible but heavy corrosion protection is not the primary concern.

Key Features

• Case-hardened 1010 steel construction for improved surface hardness under load
• Black oxide finish reduces surface friction and provides light corrosion resistance
• 13/32 inches inside diameter fits standard 3/8 inch screws and bolts
• 7/8 inches outside diameter distributes clamping load across a broad bearing surface
• 3/16 inches thickness provides rigid, non-compressible load transfer
• Inch-system dimensions for compatibility with standard imperial fastener hardware

Compatibility

Designed as an OEM-style standard flat washer for use with 3/8 inch screw and bolt fasteners in inch-system hardware applications.

Installation Notes

Installation of flat washers requires no special tools beyond the wrench or driver used for the fastener itself. Always power down or de-energize equipment before installing or removing fasteners in electrical or HVAC assemblies. Do not substitute washers of a different inside diameter, outside diameter, or thickness for applications requiring specific load distribution or clearance tolerances. Follow applicable mechanical codes and equipment manufacturer torque guidelines for the fastener being used.