Zander & Spork, As specified in ASME Y14.5M - 1994
- Section 1.8 Dimensioning Features
-- Sub-Section 1.8.1 Diameters Where the diameters of a number of concentric cylindrical features are specified, such diameters should be dimensioned in a longitudinal view if practicable. My Interpretation: If multiple diameters are involved, it is always clearer to dimension diameters & depths in a section (side) view as opposed to the plan view. In this way, there can only be one interpretation per the print.
-- Sub-Section 1.8.9 Round Holes Where it is not clear that a hole goes through, the abbreviation THRU follows a dimension. My Interpretation: The "THRU" abbreviation should be used for clarification as needed. I have also worked in the capacity of a Checker and have been responsible for company standards and meeting the requirements of various specifications. Whenever in doubt, I have always used the terms "THRU", "THRU ALL", "THRU ONE WALL", "THRU BOTH WALLS", etc. Whatever it take so that there can only be on interpretation and that the drawing stands alone. The last two requirements are also per ASME. Regards, Eddie