This smaller size of machine nut is perfect for the TeacherGeek "Buildings & Bridges" activity. They easily fit most #8-32 threaded screws, which are long enough to fasten TeacherGeek components including connector strips together into various bridge, lever and support mechanisms. A versatile solution for diverse STEM | STEAM | Maker projects. Great to use with: #8, 3" (50mm) Bridge Screws