Geometrical Dimensioning and Tolerancing for Design, Manufacturing and Inspection: A Handbook for Geometrical Product Specification using ISO and ASME Standards, Second Edition

By Georg Henzold

Chapter 21: Differences between ISO Standards and other Standards

21.1 ASME Y14.5M 1994, ANSI B89.3.1

In the following the terminology of ASME Y14.5 is used (see Table 21.3).

21.1.1 Symbols

The National Standard of the United States of America ASME Y14.5M-1994 specifies in addition to or deviating from ISO 1101 the symbols and drawing indications shown in Tables 21.1 and 21.2.

Table 21.1: Symbols according to ASME Y14.5M
Symbol	Designation	Interpretation
	ALL AROUND	Profile all around applicable to the bounded line shown
ALL OVER	ALL OVER	Everywhere, applicable to all surfaces (e.g. of a casting) ^[*] (ASMEY14.8)
	DATUM	Datum (former ANSI Y14.5) ?-ace. to ASME Y14.5 as ISO 1101:
	REGARDLESS OF FEATURE SIZE	According to ANSI Y14.5 -1982 to be indicated with positional tolerances, if applicable According to ASME Y14.5 the meaningof applies without indication (as according to ISO 1101)
AVG	AVERAGE	Arithmetical mean (e.g. of the actual sizes of a flexible ring, see flexible parts)
	TANGENT	Tolerance applies to the contacting (tangential) element
	BETWEEN	Tolerance applies to a limited segment of a surface between designated extremities
CR	CONTROLLED RADIUS	Controlled radius ("fair curve without reversals, radii at all points within tolerance")
	STATISTICAL TOLERANCING	Statistical tolerance SPC required
^[*]Not specified in ASME Y14.5M but usual in US practice.

Table 21.2: Drawing indications according to ASME Y14.5M
Drawing indication	Designation	Interpretation
	UNILATERAL TOLERANCE INSIDE UNILATERAL TOLERANCE OUTSIDE BILATERAL TOLERANCE UNEQUAL DISTRIBUTION
	ASME Y14.5: ISO 1101: ASME Y14.5:ISO 1101: COPLANARITY