9. What is the maximum thickness of grating I can use? The maximum thickness of grating that can be “sandwiched” between the T5 and the J-bolt or L-bolt is 1 3/4″. If thicker grating is used, you will need to replace the standard hardware. Paxton Guidroz Share This Story, Choose Your Platform! FacebookXRedditLinkedInTumblrPinterestVkEmail About the Author: Paxton Guidroz