On Fri, 05 Nov 2010 19:32:22 GMT, Red Green
wrote:

Be it Sears, HF, HD, etc.

They often go 6,7,8,10,11,12...

Not always in larger sets. But like who would buy an SAE set of any size if
it ran from say 3/8 to 3/4 without a 9/16?
When's the last time you really needed a 9mm wrench? In the Ansi/ISO
standard there is only 7,8,10,13,16,18,21,24,and 30
The German (Predominantly) DIN standard has only
7,8,10,11,13,17,19,22,24,27, and 30mm
The Japanese (JIS) standard uses only 7,8,10,11,12,14,17,19,and 22.

Someplace someone has slipped in a 15mm, as it is included in some
metric tool sets - so why would you want a 9 mm wrench. It doesn't
even match up to a fractional size, falling between 3/32" and 23/64"