M6-1.0 x 55mm ISO 4762 Hex Drive Class 12.9 Black Oxide Finish Alloy Steel Socket Cap Screw / THREAD DIRECTION: RIGHT-HAND THREAD LENGTH: 18.0 MILLIMETERS NOMINAL FASTENER LENGTH: 55.0 MILLIMETERS NOMINAL HEAD STYLE: C48 FLAT FILLISTER HEAD DIAMETER: 9.78 MILLIMETERS MINIMUM AND 10.22 MILLIMETERS MAXIMUM HEAD HEIGHT: 5.70 MILLIMETERS MINIMUM AND 6.00 MILLIMETERS MAXIMUM INTERNAL DRIVE STYLE: D5 HEXAGON END ITEM IDENTIFICATION: 01-652-5218 NOMINAL THREAD DIAMETER: 6.0 MILLIMETERS WIDTH ACROSS FLATS: 5.02 MILLIMETERS MINIMUM AND 5.14 MILLIMETERS MAXIMUM THREAD PITCH IN MILLIMETERS: 1.0 COLOR: BLACK OVERALL MATERIAL: STEEL PROPERTY CLASS 12.9 OVERALL MATERIAL DOCUMENT AND CLASSIFICATION: ASTM F568M SINGLE MATERIAL RESPONSE OVERALL SURFACE TREATMENT: ZINC OVERALL SURFACE TREATMENT DOCUMENT AND CLASSIFICATION: D60, TYPE I, PER FM100 ASSN STD SINGLE TREATMENT RESPONSE OVERALL THREAD SERIES DESIGNATOR: M