Black Washer - 7/16 ID x 13/16 OD (1)

The ARP Black Washer – 7/16 ID x 13/16 OD is a precision flat washer engineered for high-strength fastening applications where load distribution and vibration resistance are critical. Manufactured from chromoly steel with a black oxide finish, this washer is designed to perform in demanding environments where standard hardware falls short. The 7/16-inch inner diameter and 13/16-inch outer diameter combination provides optimal surface contact area relative to bolt size, making it ideal for applications requiring superior clamping force and reduced stress concentration.

With a thickness of 0.12 inches, this washer delivers the bearing surface necessary to prevent fastener head embedment into softer materials while maintaining the structural integrity of critical joints. The chromoly construction provides hardness and fatigue resistance superior to mild steel alternatives, making it essential for applications subject to cyclic loading or high-torque conditions. The black oxide coating offers corrosion resistance while maintaining a low-profile aesthetic suitable for both tactical and industrial assemblies.

This washer serves precision-critical bolt assemblies in firearm platforms, optics mounting systems, rail interface components, and specialized mechanical assemblies where hardware reliability cannot be compromised. Whether securing scope mounts, buttstock components, rail sections, or critical fastener points on duty firearms, the ARP Black Washer ensures consistent load distribution and vibration dampening. Professional armorers, gunsmiths, and equipment manufacturers rely on chromoly washers of this specification for applications where component failure is not an option.

ARP (Advanced Racing Products) has established itself as a trusted source for high-strength fastening hardware across racing, aerospace, and tactical industries. The MPN 200-8510 designation confirms this as a special-purpose washer built to exacting tolerances. Individual washers are sold as single units, allowing buyers to source exact quantities needed for their specific assembly requirements without excess inventory.