Carriage Bolt Square Neck Round Head Medium Carbon Steel Zinc Size 5/8-11 Length 3 In Head Diameter 1.344 In Head Height 0.344 In Square Width 0.642 In Square Height 0.344 In Drill Size 41/64 In Tensile Strength 120 000 Grade 5 For Use With Grade 5 Nuts Meets/Exceeds ASME B18.5 and SAE J429 Package 25