Supreform Universal Industrial Heavy Duty 3/4" J-Bolt Gate Hinge Steel Pivot Hinge Welded Hinge for Welding on The supreform 3/4" steel J-Bolt Adjustable Barrel hinges provide full range of swing for gates and doors. Made of high quality steel. The threaded arm allows you to easily adjust the distance between gate and post. Iron or Steel Gates, Adjustable 4 1/2" Long