Insert Washers - 1/4 ID (10)

ARP Insert Washers with 1/4 inch inner diameter are precision chromoly fastening components engineered for high-performance engine assembly and critical motorsports applications. This set of 10 washers features a 0.562-inch outer diameter, 0.318-inch insert OD, and black oxide finish, providing corrosion resistance and reliable load distribution across head bolt applications where heat cycling and extreme pressures demand component integrity.

The chromoly construction with black oxide coating delivers superior strength-to-weight performance compared to standard steel washers. The 1/4 ID and insert geometry are precision-engineered to seat properly on ARP head bolt studs, creating uniform clamping pressure across the cylinder head surface. This specification matters in high-boost, forced-induction, and naturally aspirated engine builds where consistent preload and even stress distribution prevent gasket failure and head lift under combustion forces. The black oxide finish provides reliable corrosion protection in engine bay environments without adding significant thickness.

These washers are essential for builders, performance shops, and engine builders working with ARP fastening systems on competitive engines, restorations, or engine rebuilds where original fasteners have been upgraded to ARP studs. The set of 10 covers a complete head bolt kit for most small-block to mid-size engine applications. Proper washer selection ensures bolt preload is maintained across temperature extremes and prevents galling or thread degradation during installation.

ARP fastening components are engineered to exacting tolerances and are recognized throughout motorsports for reliability under extreme conditions. Stocking genuine ARP washers ensures compatibility with ARP studs and maintains the integrity of a complete fastening solution.