5/16-18 X 3 Carriage Bolt Zinc Plated Grade 2

A Carriage Bolt Has A Square Shoulder Under A Rounded Head Which Resists Turning When The Nut Is Tightened Or Removed. They Are Good For Wood-To-Wood Connections When The Head May Not Be Accessible For Tightening. They May Be Used In The Construction Of Docks, Swing Sets And Decks As Well As Other Surfaces Where A Smooth Finish Is Needed.