The Swedes notably hit three goals in the space of as many minutes in a decisive second period.
Sweden will now face Switzerland who saw off Canada 3-2 in their semi-final.
After cruising through the pool phase Sweden were put to the test by Latvia in a 3-2 quarter-final win. But any American hopes of doing likewise melted before the halfway point of a decidedly one-sided encounter.
A 15th-minute goal by Viktor Arvidsson may have left the USA with some belief of getting back into contention. But a three-minute lapse in concentration during a more lively second period proved costly.
After Magnus Paajarvi doubled Sweden's advantage on 28 minutes, Patric Hornqvist tripled it three minutes later. To rub salt into the wounds, Mattias Janmark hit Sweden's fourth just 10 seconds later.
A desperate manoeuvre that saw the Americans remove their goaltender eight minutes from the final whistle, thus deploying an extra forward, had an adverse effect.
Arvidsson hit his second, into an empty net, in the 52nd minute with Adrian Kempe rounding off the win with a goal on 58 minutes.
Untouchable in offence, Sweden were quick to also pay tribute to goaltender Anders Nilsson, who saved a massive 41 shots on his way to a clean sheet.
The Swiss followed up their quarter-final win over Finland with an impressive triumph over Canada to set up a repeat of the 2013 final won by the Swedes 5-1.
Tristan Scherwey, Gregory Hofmann and Gaetan Haas were Switzerland's scorers on Saturday against a Canadian team missing a host of NHL stars.