Gas can nut

thingiverse

I have had a couple of plastic gas cans over the years whose fill spout nuts had cracked. Sometimes replacements are available, but often they're not. In other cases, buying the entire nozzle assembly is necessary, which can be expensive and may not match the original style. Unfortunately, sometimes the can itself must be scrapped. I have a favorite five gallon gas can with a cracked clamp nut, as shown in the photos. It's a Blitz brand that has sadly gone out of business, and I also have two other Blitz cans that will receive printed nuts when (not if) their nuts fail. The original nut was poorly designed, too thin and weak at the top where it met the threaded portion. Other designs on this website caught my eye, but none were quite what I wanted. So I decided to design one myself. Choosing the right material was the hardest part of the process. ABS would have been more pliable, but it's not known for holding up well with gasoline exposure. Therefore, I chose PLA. Closer examination showed that the seal ring on the nozzle body prevents gasoline vapors from reaching the nut anyway, making either material suitable. Nylon or PETG would also work if you happen to have them available. However, you'll need to be careful about material shrinkage since it's a tight fit initially. You may want to print a "test" nut with low fill and thin walls first. See how it fits and adjust your slicer accordingly to compensate for shrinkage and thread pitch in the final print. This particular nut has proven very strong, holding up for about three years now (as of December 2019) with no signs of change or deterioration. And because I designed it with large gripper ribs, it's actually easier to tighten and remove than the original was. I hope this helps you. It was fascinating to watch the threads being printed.