Incidentally, this is much of the reason everyone else wanted you to not. 
but what is it?
The A-Team did a lot of welding as I remember. Normally at the start of the build montage.
Crowfoot spanner
[quote] but what is it? --- monkimark [/quote]Probably used the 11mm socket that never gets used, unless you're building an impromptu bong.Crowfoot spanner
TimR
Socket torque wrench spanner?
Has anyone ever used the 11mm socket for anything?
raises hand
+1 and the 7/16th
What was it?
raises hand
National Treasure
I’m also sure I’ve used it… not sure on what though
Probably by accident when you couldn’t find tbe one you were supposed to be using 
My first socket set contained AF, WW and metric sockets including the 11 mm which, back in the day, probably saw the most action of the metric offerings alongside the 12 mm. Proper handy those two for dealing with rounded off 7/16" and 1/2" AF hex bolt heads which were a popular size found on pre 70’s engines. Probably still a popular size on the likes of Harley’s and other American vehicles. My most recent use for the 1/2" was dealing with a rounded off 13 mm sump plug.
More recently 11mm hex bolts appear to be favoured by the furniture industry, Spaceright’s range of school dining tables use them to secure the seating and IKEA used them on their now obsolete GORM range of timber based shelving, very popular in garages, workshops and sheds around the world because of its cheap price tag, versatility and robustness. Never understood why IKEA dropped the range in favour of the lesser ALBERT, HEJNE and IVOR designs.