From factory the J-Bolt Gate hinge is too large, the gate will sag -how do I fix it?
If you just hung the gate on one set of these it would be a problem. Also if you just used one bolt to hold the strap to the gate it would be a problem. 

With that said if you build your gate as a rectangular element with proper cross brace so that the gate itself keeps its shape and then mount the straps to the gate with two bolts each you will not see gate sag due to the larger size hole in the strap versus the size of the post on the L-bolt.