# What are the meanings of B.C. 3/8“ and 6-11/32”?

I'm totally ignorant in this area, and probably didn't know how to properly google my question - sorry..

I found this specification here: (https://si.shimano.com/pdfs/ev/EV-RH-IM10-2045B.pdf). My guess is that M10 is the about the metric thread specification (https://en.wikipedia.org/wiki/ISO_metric_screw_thread). But what is the meaning of B.C. 3/8" then?

Another question about this spec: (https://si.shimano.com/pdfs/ev/EV-FH-2200-2202B.pdf) - what would be the meaning of 6-11/32" - it can't be a range, or can it?

I think 6-11/32"means 6 inches and (or plus if you prefer) 11/32 of an inch. Indeed, if you do:
(6 + 11/32) * 25.4 = 161.77mm