John B. wrote:

It is the external width of a 9S chain,
all brands.

Are you saying that Shimano may be selling
a 9 speed chain that doesn't fit?

I'm saying that's all the data I have on
9S chains. "All brands" includes Shimano,
assuming the information is correct that is.
Check with a calipers or a micrometer...

What does it say on the boxes, for the HG 53
and HG 93, except for the
Deore/Tiagra/Ultegra/XT stuff?

It says that it is a 9 speed chain :-)

Oh, c'mon now! Even on the boxes to my single
speed standard bike chains it says,
e.g., Ventura 1/2x1/8" 112L, that it comes with
a master link, a side plate and a retaining
clip, and more...

--
underground experts united
http://user.it.uu.se/~embe8573