Flange Bolt, 5/8"-18, Steel, Plain, PK 15/ THREAD DIRECTION: RIGHT-HAND FASTENER LENGTH: 3.250 INCHES NOMINAL HEAD STYLE: C1 HEXAGON HEAD HEIGHT: 0.625 INCHES NOMINAL HARDNESS RATING: 33.0 ROCKWELL C MINIMUM FASTENER AND 39.0 ROCKWELL C MAXIMUM PART NAME ASSIGNED BY CONTROLLING AGENCY: HEX HEAD CAP SCREW SPECIAL FEATURES: FINISH-PLAIN; 0.938 INCHES HEX WIDTH; THREAD STYLE - PARTIALLY THREADED; SCREW GRADE/CLASS GRADE 8 STEEL FINISH; SCREW INDUSTRY STANDARD - IFI-111, TENSILE STRENGTH - 150,000 POUND PER SQUARE INCH (PSI); 1.313 INCH FLANGE DIAMETER; 0.10 INCH FLANGE THICKNESS; 0.625 INCH DIAMETER; THREADED LENGTH - 1.50 MINIMUM TO 2.273 MAXIMUM INCH THREAD SERIES DESIGNATOR: UNF