A machine shop guy I was having stuff done with told me a decent flat tolerance is within 5 thousandths of an inch.

He said they regularly take stuff down that far, and i was having him bore some things out where only a few thousandths needed to be removed for a sliding tolerance.

I found on wikianswers that a thousandths is .0254 of 1mm

I figure if 5 thousandths is only .0254 of 1mm, and they get that fine all the time, making something correct within a mm should be an easy job for any machine shop worth its salt.

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