If a product feature has a dimension of 1.8 + .03, what is the lower tolerance dimension?

To determine the lower tolerance dimension for a product feature expressed as 1.8 + .03, you start with the nominal dimension, which is 1.8. The "+ .03" indicates the upper tolerance limit, meaning that the feature can be as large as 1.83 (1.8 + 0.03).

To find the lower tolerance dimension, you consider the standard practice of tolerancing where the lower limit is derived by subtracting the tolerance from the nominal dimension. In this case, the tolerance is not specified as a negative amount, so we simply assume that the feature can go down to a certain minimum that adheres to the overall tolerances defined.

By calculating this, you would take:

Nominal dimension of 1.8 - the tolerance represented by the "+ .03" sheet allows for the lower tolerance dimension of:

1.8 - 0.03 = 1.77

This shows that 1.77 is indeed the minimum allowable dimension given the positive tolerance of 1.03. Therefore, the lower tolerance dimension is 1.77, making it the correct answer.