Nominal position?

Question

On an engineering drawing it says 'at this nominal position'

can someone tell me what this means.

Answer 1

Nominal is the position or dimension at which it should be.  All dimensions in an engineering drawing have tolerances, since it is impossible to measure something exactly.  For example, a dimension might be 1.50 ± .02 in.  The actual dimension could be anywhere between 1.48 in. and 1.52 in., but the nominal dimension is 1.50 in.

Answer 2

That means not considering any tolerance on dimensions or positions, only at the "average" position.