turning point

(mechanics, automotive) set of operations to test and tune an appliance, engine, etc. before production; setting up, tuning / (computer science) search and correction of bugs in the development of computer code

about to, on the point of

(idiomatic) abruptly, suddenly, out of the blue / (idiomatic) cold turkey

(physics) zero-point energy

plural of energia di punto zero

(aviation, also figurative) point of no return

strut, rafter / battering ram

plural of puntone