Brand: Automotive Racing Products (ARP)
These high-strength (180,000 psi) chrome moly nuts are a perfect match for ARP 1/2-20 Black Oxide Bolt 5-Packs (sold separately).
The 1/2-20 UNF (fine thread) nuts take a 9/16" 12-point socket, but they have a full 0.823" OD bearing surface, similar to the matching ARP 726 Series bolts. Head measures 0.51" high overall. The black oxide finish looks great and is easy to paint if desired. Pack of 10 nuts.