If you wanna print it yourself, the model is here: https://www.printables.com/model/1348194-4n-threaded-flat-head-screws-and-nuts-10-32-equiva
Design to be a drop in replacement for 10-32 screws with a much, much higher pitch. These screws are extremely easy to print, is reliable enough that it can hold some weight.
If you wanna print this yourself, you need to make sure that the screw is sideways, so if it breaks it’s no on the layer lines.
Using them in my own prints which had metal screws and they are holding quiet well.
Having single pointed 3"-4 Buttress threads on a manual lathe for punch presses more than once and hand grinding the tool bit from 1/2" x 1" HSS, I still have some PTSD over that thread form. But hey, if you are looking to make breaching for a 16" Navel Rifle, it’s really the only game in town…
As a toolmaker, I have seen Buttress threads used in only 3 places. Large artillery breaching, punch press ball screws, and VERY high end, (read expensive), machinist clamps. I own a pair I picked up at an auction 30 years ago in a bucket of “junk”. I think they were made by another machinist for personal use.
Edit to add: Buttress threads are directional. They can be either left or right. The choice being totally dependent the direction of the force applied to the threads. The perpendicular edge is the strong part. And the direction must always be called out.
Thanks so much. I did not know the original purpose of the profile. In my experience with 3d printing, the buttress profile strength is in the opposite orientation when printed vertically. The additional length of the tapered profile creates a better distributed load across more layers of the stretching member/fastener. Still, I will prioritize overall printability without supports over thread directional orientation in most cases. I’m usually using a very large custom sized thread where the thread strength is irrelevant.
Like here in my laptop GPU water cooler project, I am using a buttress thread and spline to retain the cooling block and pump.
At that diameter, I would probably recommend a bottle cap thread. It’s a rounded profile that is easy to print.
Walls are too thin for a bottle and with the cut for r&i I would expect it to have issues at the seam. Even with this, the seam requires holding until it starts to get touching contact. Maybe if the bottle is extended past the 45°-50° tangent it would do a little better but then it has drop potential, especially with this PC/ABS blend and no part fan in an enclosure.