This is a shelf rest bracket I designed to replace broken ones in our kitchen pantry, but I imagine it could be used in a variety of different kitchen and office cabinets and also for book shelves. It is designed specifically for a 11/16" thick shelf but should also work well for a 5/8" thick shelf. It could possibly even be used for a 3/4" thick shelf, but the upper tab will not flex out above a that thick of a shelf to fully lock it. The peg/ stud on the factory shelf rest measured approximately .268" across at the highest points on the lobe features, so that is the dimension that I used for this design as well. At this size, it should work well for a number of hole sizes around 17/64"

I printed it laying down, and although this uses a little more support, it keeps the peg/ stud part of the design in the cleanest shape. It could also possibly be printed on its side, which may yield slightly more strength (so far I have not had any issues and there is a lot of weight on the pantry shelf) and use less support but the peg/ stud would not be as clean in the print.

Hope this bracket can be of use to you!
Enjoy!
-Ryan