01-19-2018, 01:24 PM
Most machinists use a complete drill index to gauge small holes because calipers are prone to measurement errors. Find the last bit that will fit in the hole (use the smooth end) and the first one that doesn't fit and you've gauged a hole measurement within an acceptable range of tolerance.
I couldn't do my own work without a drill bit index (plus a tap and die set) so I've got them on hand to use. Always tighten drill your chucks adequately so that the bits don't spin and get marred, which will ruin them for gauging purposes.
I couldn't do my own work without a drill bit index (plus a tap and die set) so I've got them on hand to use. Always tighten drill your chucks adequately so that the bits don't spin and get marred, which will ruin them for gauging purposes.