surface finish question

If I have an ID that calls out for a ream of .4720+-.0005, would it be
posible for it to be inspected to a +-.003? I was asked to put this
runout on a drawing and I'm thinking at 4 places with a +- in 4 places
the ream would never be that loose.

Any one have something on this?

Thanks

Frank

 

The purpose of the tolerance on the hole size is to ensure that you get an interference fit on a 12mm pin. The purpose of the runout tolerance (or profile tolerance) is to ensure that the mating part can line up with the dowel, even if the hole is not perfectly straight. BTW, the runout tolerance does not effect the size of the hole. So, no, I don't think it's contradictory to specify different tolerances on size and location/condition of the hole. Especially not when you're translating from metric to US Customary (English, Imperial units, whatever you want to call them) where a mere sixty-fourth tolerance takes 6 places to express evenly.

David Janes

 

OK David, thanks for getting me thinking right again.

Frank McDougle