@octane_workholding: Old School Machinist Trick For those wondering. It can be difficult to start a tap perpendicular to the workpiece without some sort of guide. Threading the nut onto the tap allows progressive advancement. As the tap goes deeper, the nut follows and provides a surface to help keep the tap from wandering. The tap in this video was 1.00"-8 and would obviously have been easier with the machine. This was a demonstration of a neat old school technique.