Home Forums Hunting & Shooting Ask The Gunwriters Question about metric conversion

.001mm measures .000025 of an inch, or 25 millionths of an inch, also called a micron. To get a surface finish near a 25th of a 10 thousandth, or .000025 of an inch we would have to send the part out to grind as the surface finish on the part after machining in a lathe would be too rough to measure a micron. In fact I have no idea how you would measure a micron in a machine shop. That said I have never seen the micron symbol on a CNC lathe set to the metric measure. This illustrates the out of sync dimensions of metric. The micron being too small, the millimeter being too large so you have to break it down, the centimeter a semi useful measurement and the meter virtually never used. So yes a micron is smaller than .0001. That said if the machine can measure precisely enough for microns it can also measure .00001, however how a shop would measure the finished part to that tolerance I have no idea.