ARP 3008330 Stainless Steel 1/4-28 12-Point Nuts - Pack of 10 12-point style is more compact than traditional hex style Thread size is 1/4 - 28, and socket size is 5/16 Constructed from the finest aerospace-quality polished stainless steel Rated at 180,000 PSI, which is considerably stronger than Grade 8 hardware Package contains 10 nuts, each of which meets ARP's exacting quality control standards