Gibraltar 63605G M12 Standard Flat Washer Black Oxide

Product Description

The GIBRALTAR 63605G is an M12 standard flat washer manufactured from grade 1010 case-hardened steel with a black oxide finish. It is designed to distribute load under a bolt head or nut, reduce surface damage, and prevent fastener loosening in bolted assemblies. With an inside diameter of 0.512 inches (13 mm), an outside diameter of 1.142 inches (29 mm), and a thickness of 0.118 inches (3 mm), this washer meets standard metric sizing for M12 fastener applications. Machinists, millwrights, maintenance technicians, and trade professionals install these washers in mechanical, structural, and equipment-mounting applications where a metric fastener system is specified.

This washer is suited for use in industrial maintenance, commercial equipment assembly, and general mechanical repair work where M12 fasteners are used. The black oxide finish provides mild corrosion resistance and reduces light glare in finished assemblies. It is appropriate for interior and sheltered exterior applications where moderate environmental exposure is expected. Sold individually per package, with a minimum order quantity of 10 pieces.

Key Features

• Grade 1010 case-hardened steel construction for improved surface hardness and wear resistance
• Black oxide finish provides mild corrosion resistance and a clean, low-glare appearance
• Standard metric dimensions: 13 mm ID, 29 mm OD, 3 mm thick
• Designed for use with M12 fasteners in metric bolted assemblies
• Lightweight at 0.05 pounds per piece, minimizing added load in assemblies

Compatibility

Designed for use with M12 metric screws and bolts in standard flat washer applications. Suitable for mechanical assemblies, equipment mounting, and structural connections specifying an M12 fastener with a standard washer pattern.

Installation Notes

Installation is performed by machinists, millwrights, or maintenance technicians as part of a bolted assembly. Place the washer between the fastener head or nut and the mating surface before torquing. Ensure the correct washer series and material grade are confirmed against the assembly specification before installation. Verify that the black oxide finish is appropriate for the service environment, as black oxide alone provides limited corrosion protection in wet or chemically aggressive conditions.