https://youtu.be/k7n_5CkW5yQ "Bolt Box" is a 3D printed dual nut version of a single nut puzzle box I'd seen at craft shows over the years. A friend (and follower) asked if I could recreate the dual nut version (which is currently commercially available as "Nut Case") for 3D printing, so here it is. I designed this model in about thirty minutes using Autodesk Fusion 360, and 3D printed the four pieces in under an hour. However, assembly and subsequent solving of this puzzle may take hours! I 3D printed this puzzle on my Ultimaker S5s using the Ultimaker Cura 4.6.1 "Engineering Profile" (which provides highly accurate tolerances) at .1mm layer height with 100% infill. After printing I used jewelers files and Micro Mesh sanding strips along with plenty of patience to remove the build plate "ooze" (sometimes referred to as "elephant foot") and thread sag from each piece. Depending on your slicer, printer, printer settings and the colors you chose, you may need more or less filing and sanding. As usual I probably forgot a file or two or who knows what else, so if you have any questions, please do not hesitate to ask as I do make plenty of mistakes. And if you need any assistance in assembling this puzzle, just comment and I will do my best! I hope you enjoy it, and best of luck in solving this puzzle! Designed using Autodesk Fusion 360, sliced using an Ultimaker Cura 4.6.1 "Engineering Profile", and 3D printed in PLA on an Ultimaker S5.