1 .1
The purpose of this Standard is to provide guidance in the selection of preferred numbers for use in
standardization, rationalization, and size selection, leading to a degree of variety control that would
othewise be difficult or impossible.
1.2
Preferred numbers are independent of any measurement system and can, therefore, be used with any
system of units, with currencies, with dimensionless quantities, etc.
1.3
This Standard concerns itself with numbers that form geometric series rather than those that form
arithmetic series. Examples of how the latter numbers are used may be found in CSA Standard
CAN3-A31 , Series of Standards for Metric Dimensional Co-ordination in Bui/ding, and IS0 Standard
3394, Dimensions of Rigid Rectangular Packages -Transport Packages.