Muffin Tin Attach a muffin tin under a shelf with a single 1/4-in. x 1-1/2-in. flat head machine screw. The tin pivots out from beneath work surfaces. For best results: -Use muffin tins made from heavier gauge metal. -Drill & countersink a 1/4-in. hole in the shelf top, so the top of the screw is flush with the shelf. -Place 1/4-in. fender washers above & below the rim of the muffin tin. -Tighten two nuts against each other on the underside so the threads won't loosen.