26 Conversational topic “Drawings” should include

Precision and tolerance it is impossible to produce components with dimensions that are absolutely precise, with as those specified in a design. This is because all production processes are imprecise to a certain extent. Because engineers know that accuracy cannot be perfect, in designs they often specify tolerances - that is, acceptable variations in precision. Instead of giving one precise size, a tolerance specifies a range of acceptable sizes - an allowed amount of variation. This is often given as a deviation from a precise size.