AS Z30-1966

FOREWORD1 SCOPE2 DEFINITIONS3 TYPES OF DIMENSIONS 3.1 Individual toleranced dimensions 3.2 General toleranced dimensions 3.3 Non-toleranced dimensions 3.4 Datum dimensions 3.5 Tolerances without an associate dimension 3.6 Designating dimensions4 BASIS AND ACCURACY OF CONVERSION 4.1 Conversion factors 4.2 Basis of rounding 4.3 Method of rounding 4.4 Application of general and special roundings 4.5 Accuracy of conversion 5 CONVERSION PROCEDURES 5.1 Individually toleranced dimensions 5.2 General toleranced dimensions 5.3 Non-toleranced dimensions 5.4 Datum dimensions, positional tolerance and associated dimensions 5.5 Tolerances without an associated dimension 5.6 Designating dimensionsAPPENDIX A-EXAMPLES OF CONVERSION APPENDIX B-TABLES OF EQUIVALENT VALUES B1 Decimals of an Inch to Millimetres (exact values) B2 Decimals of a Millimetre to Decimals of an Inch (approximate values) B3 Fractional Inch Sizes to Millimetres B4 Inches to Millimetres (exact values) B5 Millimetres to Inches (approximate values) B6 Metric Equivalents of Inch Values from 0.001 to 0.999 Inch B7 Metric Equivalents of Inch Values from 1 to 999 Inches B8 Inch Equivalents of Millimetre Values from 0,001 to 0,999 Millimetre B9 Inch Equivalents of Millimetres Values from 0 to 999 Millimetres B10 Metric Equivalents of Feet Values from 1 to 999 Feet B11 Feet Equivalents of Metres Values from 0 to 999 Metres

Establishes rules for the conversion of inch dimensions into millimetres and vice versa, and applies mainly to toleranced dimensions where accuracy of conversion is essential to ensure interchangeability, use of original gauges, identity of fits, etc.; non-toleranced dimensions and their conversions are also dealt with. Tables of exact millimetre equivalents of inch values from 0.001 to 999 in. and of inch equivalents of millimetre values from 0.001 to 999 mm to seven decimal places are included, and also tables covering the conversion of feet to metres and vice versa. Illustrated examples of conversions are provided and the Standard also includes definitions of some of the more important terms covering sizing, tolerances, etc.

This standard establishes rules and recommended procedures for the conversion of inch dimensions into millimetres and vice versa.It is mainly concerned with toleranced dimensions where the accuracy of conversion is important to ensure interchangeability, use of original gauges, identity of fits, etc. Consideration is, however, also given to non-toleranced dimensions, their varieties and their conversion.The standard also provides tables of the exact millimetre equivalents of inch values from 0.001 to 999 inches and tables of inch equivalents of millimetre values from 0,001 to 999 millimetres to the nearest value in the seventh decimal place.For those concerned with measurements in feet or in metres, two tables covering conversion ranges of 1 to 999 feet and of 1 to 999 metres, are provided. These tables can also be used for values incorporating decimals of a foot (or of a metre) by the method of movement of the decimal point to the left.

Reconfirmed 1984