Actually a pretty interesting discussion about wrench sizes.

Back in the old days of standard sizes, the fractional measures suggested a hierarchy of popular sizes that pretty much everybody understood - few would choose 15/16 or 31/32 when they could just pick 1".

However, in metric, no millimeter size is really any more obvious than the next. This works great in the 4-10mm range because people need all those sizes, but as you get into the teens and especially the twenties and thirties, you start to need extra wrenches due to nothing more than a lack of standardization.

On an unrelated note, I have a 4, 4.5, and 5mm sockets. I think I even actually needed the 4.5 once or twice (not on bikes).

Not on any modern geared bike. I guess my single speed commuter bike does use bolts (I forget the size) on the hubs. But anyone who would actually buy an entire set of wrenches for $1.25 is nuts.

i recall having so many variants of 10 and 12mm wrenches and sockets in my car modding days, must have been a dozen sockets and a similar number of wrenches.

My favorite use of a closed-end wrench is turning my crank extractor. I run the extractor through the closed end of a combination wrench before I screw it onto the bike. Then I have a nice 6-point wrench to push hard on. While I can't take the wrench all the way off until I'm done, I can reposition it at will.

Actually sometimes you do need a ring spanner, because they have narrower shoulders than an open-ender and can turn 30° at a time. There are jobs on cars where you should be removing a major component for access, but you can avoid that if only you could turn those two hard to reach bolts ...

The 13 is for when you lose your 1/2

I worked on a lot of European cars BITD - Fiats, Peugeots, Citroens, etc. - and they all had those sizes, except maybe the 12, only very old Citroens used that.
5mm bolt = 8mm wrench, 6 = 10, 8 = 13, 10 = 17. On Citroens, 7mm = 11 or 12.

Of course. Any of those are considered lethal.

Dollar stores sell what they can get cheap. They don't pay anyone to figure out what customers want. It's possible this set is at the dollar store because no one else wanted it, possibly because the manufacturer made a mistake.

Speaking of odd tools, the Osco drug in Cedar Rapids used to sell bizarre stuff. I remember a 1-inch drive socket set, the largest socket 3⅛. I think they also had an arc welder once.

I checked my metric wrench and socket sets

MAC metric 3-8" drive 6pt. socket set - short and long...10-19 mm sans the 11 and 18

Craftsman 1/2" drive 6pt. impact socket set 10mm-24mm, sans 20mm and 23mm

Craftsman 1/4" drive 6pt socket set ...5mm-14mm all inclusive

Craftsman 12pt. pass-thru socket set 10mm-19mm, sans the 16mm

Craftsman combination wrenches 10mm-18mm, sans the 11mm.

I recall Sears selling sets with all kinds of unusual combinations. In their case, it sure seemed a ploy to sell more tools.

Looking at that picture I would probably go to Harbor Freight first than buy that set. But if you were stranded with a bad car battery those wrenches would probably let you get that battery out. I've used combo wrenches (open side) on Look pedals.

scott s.
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The 19 is for when you can't find the 3/4