On Thu, 22 Oct 2015 17:52:45 -0400, Stormin Mormon
wrote:

On 10/22/2015 4:30 PM, wrote:
You need 2 sets, and for the metric set it depends what vehicle you
are working on and where the set originates. Some vehicles only use
8,10,12,15,17,19,21 and 24
Others use 8,11,13,16,18, and 22
Others use other combinations.
A "full" metric set includes everyrhing from 8mm to 28mm.

Then there are the oddball aplications (have not run across them in
automotive) that use decimal sized metrics - like 5.5

You don't need 2 of each ratchet or extension as all metric sockes (at
least in the north american market) use 1/4, 3/8, or 1/2 inch drives
for light to medium duty use, and 3/4 or 1 inch for HD use


Today I bought one eaches HF quarter inch
drive metric set, that goes to 13 MM. Will
get me in and out of most of my repair
needs. Surely would have done good for the
windshield wiper repair yesterday.

See if that set goes on sale, buy a set for
the other vehicle.
If you are only going to have one set, make it a 3/8". You can
always use an adapter down to 1/4 for the smaller sizes (10mm and
smaller)- 1/4" reatchets etc are designed for low torque - generally
no more than 20 ft lb (240 in lb)