"The Other Mike" wrote in message
...
On Tue, 3 Mar 2015 17:07:47 -0000, "mark"
wrote:

Like most on here I've got lots of spanners.
Sticking with metric sizes, I've noticed that the majority of my spanner
work is with 10mm and 13mm sizes which corresponds to M6/M8.


So what are the other ones for in spanner sets, ie., 9mm, 11mm, 12mm, 14mm
and so on. Are they just there to make the numbers up or make it harder
to
find the one you want?

There are preferred sizes defined in the standards but they are not
mandatory,
so sometimes a smaller head is used, saving weight or reducing assembly
time or
improving access.

i think a 16mm spanner is my least used size of a full set i have from 4.5mm
to 8mm in .5mm increments, then from 10mm to 19mm in 1mm increments,
i have at least 2 of 10, 13, 17 and 19mm spanners as they are the most
likely to be needed on a nut and bolt at the same time.
i then have 1 each of 22, 24, 26, 27, 30, 34 and 36mm spanners,

The larger sizes are common on the heavy campervans i once owned, they were
the reason i have a few odd sockets like a 27mm thin wall extra deep reach
one for injectors, a 3/4" drive 19mm socket used for the wheel nuts on a VW
LT (1/2 inch drive sockets either split or snapped the breaker bars square
off when trying to undo them)
And the 63mm socket used on the rear wheel bearing nuts of an iveco daily,
plus a few hex key sockets in the 20mm range, and an oddly bent short shaft
14mm spanner for the awkward nut on iveco injector pumps.

That's all small fry compared to the spanners and sockets used daily at the
commercial garage is did my YTS years at, including a torque wrench with 2
handles set at 60 degrees or so, so that 2 fitters could push and pull on it
together to get the thing to click at the set torque.