NASM 23964 Rev. 2 covers positive locking self-retaining bolts.Classification. Bolts will be of the following types and classes, as specified (see 6.2):
Types:Type I Head end actuated.Type II Thread end actuated (solid shank).Classes:Class 1 CRES bolts, magnetic (PH13-8Mo).Class 2 CRES bolts, nonmagnetic (A286).Class 3 Titanium bolts (6Al-4V).Class 4 Nickel Alloy (718).