The main identifier is the diagonal corners in the counters. the A and S also have a unique shape.
Thanks to anyone who can help.

Bessemer Bold  Suggested by donshottype 

Custom label.
No match to a retail font.
Bessemer Bold is a chamfered font, i.e. clipped angular corners, with a similar weight, width and mid height diagonal for _S_. For similar _A_ imagine a vertical flip of _U_ and add a crossbar.
N.B. the IPA label dos NOT appear to be derived from Bessemer Bold.
Hudson NY is another similar font.