In the U.S. circle wrenches are actually called box wrenches..But circle wrenches makes more sense as they are actually shaped like a circle and not a box.

Are we talking about ring spanners here?

exactly.....these Americans tinkering with our English language again!

There is a wonderful shop with every kind imaginable just across the river. Screws that is, not tools.

Just across which river from where would that shop be Jeffrey?

How many rivers does Chiang Mai have running through it ?

Cross the river by the US Consulet left side about 500 meters up

wonderful shop

all grades and types

Sounds like the same one I go to also; as I recall it is just before the first set of traffic lights. Very traditional, everything sold loose so you can buy just 6 nails or 2 washers or 42 screws....they just count them out and bag them up.

Every type and size of floorbolt, wall bolts,.all on display behind glass..fascinating but as with a lot of Thai run hardware shops...bloody filthy....but cheap....so thats a plus

If you have been past Nana screw in last 2 days you wont have failed to notice the razzamatazz, pretty girls and boys outside giving it the full verbal sales spiel, and some awful music.

Box end wrench, circle wrench, ring spanner, a rose by any other name . . .

By the way, who calls them "circle wrenches"?

No one, and I admit it was a "Senior Moment" when I tried to remember what the danged things are called...