Brand: Automotive Racing Products (ARP)
Hardened, parallel-ground ARP stainless steel washers are a great match for ARP 5/16-18 UNC Stainless Bolts or ARP 5/16-24 UNF Stainless Bolts.
These 5/16" ID washers have an oversized 0.675" OD that is larger than the 9/16" OD of AN960 washers but smaller than the 1 3/8" OD of AN970 washers. The ID is chamfered on one side for clearance on certain "super-strength" bolts, but they can be used with just about any 5/16" bolt. Extra-thick 0.120" thickness is almost like stacking 2 AN960-516 washers. Polished corrosion-resistant stainless steel. Sold in packs of 2.
| 5/16" Washer Comparison |
| Washer | OD | Thickness |
| AN960-516 | 0.562" | 0.063" |
| ARP400-8540 | 0.675" | 0.120" |
| AN970-5 | 1.375" | 0.063" |
