ASME B18.2.1 BH (supersedes MS90727F)
Alloy Steel Grade-BD Hex Cap Screws per ASTM A354 BD Zinc Yellow Plated & Baked per ASTM B633-07

Military Fastener Listing 

ASME B18.2.1 GrBD, Fine, Yellow Zinc Hex Cap Screws Stock Military Fasteners