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Profile - Unequal and Unilateral

There is an easier way to tolerance Unequal and Unilateral Profile.

The ASME Y14.41-2003 Digital Product Definition Data Practices standard has given us a new way to express several geometric tolerances. One of the most useful is the one for unequal bilateral and unilateral profile of a surface tolerances. In the interest of space, both methods of indicating unequal bilateral profile of a surface tolerancing on a drawing are illustrated. Both would not appear on a single drawing. Think of the detail view as the MEANS THIS portion. According to the Y14.41 standard, the value that follows the U in a circle is the amount of tolerance zone that applies outward from the surface. This may also be used to indicate a unilateral profile tolerance. Of course, if you want to use this new symbol, you should reference ASME Y14.41-2003 as well as ASME Y14.5-1994 so everyone reading the drawing knows where to find the meaning.

Of course, if it is designed in mm and you build in mm, this is not an issue. But, if you insist on converting metric values to inches, do it right. 

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