This standard has 5 standard cross sections, .070",.103",.139", .210" & .275"

Because the ratio of Cs to ID is a design consideration, the id range is:

• .070"=1/32" thru 5"
• .103=1/16" thru 9-3/4"
• .139"=3/16" thru 18"
• .210"=7/16" thru 26"
• .275"=4-1/2" thru 26"

These are the standards in AS568.

There are also a number of metric "standards", covering pretty much the same size range, although with different standard cross sections:

• Japanese JIS standard
• German DIN standard
• British Standard BS4518
• French Standard
• Swedish Standard

There is also a relatively new "international" standard that has come out of ISO 3601-1 and is very close to our AS568 in sizing.In addition there are the "900" sizes which are for tube fittings and the size numbers correlate to hydraulic hose size numbers
eg 912 is for 3/4", -904 is for 1/4" etc.

Now having said all this, bear in mind that these are STANDARDS. In addition, there is virtually an unlimited list of non standards. Any manufacturer of equipment who is interested in aftermarket business, that is the replacement parts, likely will design in a nonstandard size so that their customers will have to come back to them for parts. New technology allows us to offer, once again, virtually unlimited sizes.