AS Z30-1966

Table of Contents

FOREWORD
1 SCOPE
2 DEFINITIONS
3 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 dimensions
4 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 dimensions
APPENDIX 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

Abstract

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.

Scope

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.

General Product Information

Published
Document Type	Standard
Status	Current
Publisher	Standards Australia
Pages
ISBN
Committee	ME-027
Supersedes	Doc 972 (1965)