A-B1002X77MA-AI BOLT, CRG .31-18 X 2One New Aftermarket Replacement Carriage Bolt 5 16" 18 x 2" This carriage bolt (CRG) features the classic round dome head and square neck design used throughout agricultural, construction, and lawn and garden equipment assemblies. The square neck seats snugly beneath the head to prevent rotation during nut tightening, making installation straightforward without requiring access to the bolt head. Commonly used to secure implements, guards, brackets,