UNC-3A & UNF-3A. Austenitic Corrosion-Resistant Steel screws shall be manufactured from Type 304 (UNS S30400),Type 304L (UNS S30403), Type 305 (UNS S30500), Type 316 (UNS S31600), Type 316L (UNSS31603), Type 384 (UNS S38400), or Type XM-7(UNS S30430) in accordance with the chemical compositions specified in ASTM F 593. Passivate in accordance with QQ-P-35 or Black Oxide coating in accordance with MIL-C-13924, Class 4. (Except for Type 316 or Type 316L).