Fair enough. I think the real question is... Why is such a unit still being used? I was under the impression that any serious ultra-precise CAD and machining w

Fair enough. I think the real question is... Why is such a unit still being used? I was under the impression that any serious ultra-precise CAD and machining was done in milli, micro, and nanometres. I thought pretty much any serious science or engineering had been metricated... But then again I shouldn't be surprised; Americans measure the volume of lakes in 'acre-feet'...