...or what is the best font that looks like the one in black tags (SBRINATORE PARABREZZA - GENERATORE - RISCALDAM. AUTISTA-INT. - and so on)? Thanks in advance

Routed Gothic  Suggested by donshottype 

Looks like originals were made by a milling machine, which creates a monoline stroke with rounded ends, rather than direct application of a common font.
For substitutes look at some DIN rounded fonts and fonts based on the Leroy lettering guide.
For example, Routed Gothic -- NOT THE FONT -- is a passable substitute