Summary I designed this clamp in Autodesk Inventor to hold a manifold I was making as part of an air-powered bottle car launcher. The clamp fits a 1/4" NPT x 3" (or longer) brass nipple, like this https://www.fastenal.com/products/details/69873?term=1%2F4%22+Male+NPT+x+3%22L+Brass+Pipe+Nipple The bottom clamp has nut holes for M6 hardware. M6x16mm screws would probably work best, the ones I had on hand are too long but work fine. The bottom also has 4 .25" holes for mounting or bolting to your desired surface. I printed this solid on a Dimension UPrint out of ABS. The .stl was processed in CatalystEX.