This is a utility hook I designed for the French Cleat system on my workbench. My cleats are cut on 45° angles and are 19mm x 19mm.
I realize differences in French cleat designs and peoples' needs means this is much more useful if it can be easily customized so I've included the FreeCAD design file in the file archive to make design modifications easier. This design was done in FreeCAD 0.18.
I printed this laying on it's side, as shown in the STL render above. Supports to bed only.