i've got a NOS campy athena headset. I measured the cups and they're 30.2 mm, i measure the crown race and it's 26.4. Someone wanted to buy it off of me and they were asking if it was english or italian. How would i figure this out? i looked under sheldon and it would classify under ISO, but i don't know what the threads per square inch are.

here's a pic of the headset:

Typically, Campagnolo stamps the thread standard on the bottom of the locknut. Or least that's were they used to stamp it. 25.4 x 24F designates Italian. 1 x 24 designates English.

English/ISO/Italian headsets all have the same dimensions.

thanks for the reply, nothing on the locknut except for campagnolo engravings

the box says:

BC1" HS-11AT

then there's a sticker that says:
057-c-01 EA CA-HDA
Campagnolo Athena Headset
4609489 tot 3 02/15/96
52A 29

cool thanks for the heads up

But the thread profiles are slightly different in the angles and crest/valley shapes. While mixing the two is done routinely, it does result in slight damage to the threads and the buyer may be particular, which is why they are asking.

Regardess, this one would appear to be English. BC was Campagnolo's abbreviation for British Standard Cycle or BSC.

Edit: Based on the catalogs, it appears that Campagnolo had stopped offering Italian threaded headsets by this period, so that would explain why there are no markings.

And that's really my point. From the mid-90s on you have only ISO/English and JIS.

this would actually comply with the dates on this headset as it's from 1996.

thanks Tmar and ColonelLloyd