How to Measure Deep Hole Diameter: Tools and Techniques
I use bore gauges for most deep hole measurements. I have measured thousands of holes across dozens of shops, and the right tool always depends on the tolerance and the hole depth. Measuring the diameter of a deep hole is not the same as checking a conventional bore. Access is limited. The bore is long and narrow. Standard calipers and bore mikes will not reach past the first 100mm. Over the years, I have settled on five main methods that cover the full range of what I encounter on the shop floor. ...