HTML Editor – Full Version. 1/2-13 Diameter Coarse Thread 307A Grade A Carriage Bolts. Protective zinc clear finish to help prevent rust! Multiple Quantities and Sizes Available from this Listing! Looking for additional items or different quantities? We’ll be glad to help! FEEDBACK IS VERY IMPORTANT TO US! We will do our best to make it right. Our fasteners are quality inspected and manufactured to all applicable standards and specifications. These are not second quality fasteners that were previously rejected… Continue Reading ››