(Note: The sequence in the film is slightly enhanced, it turns out, with more sparkly effects
and some oil-flames added to the hammering. Why they couldn't get it right when the
TTT-M scenes showed real forging, I don't know.)

hammer raised to heated blade laid flat on anvil

hammer about to strike, reflecting glow from blade

hammer raised again

wierd color negative frame used to simulate "impact flash" in trailer.
hammer is clearly visible as hammer here.

"natural color" frame of impact, plus superimposed images of sparkler and spotlights
to add visual interest.

after having been hammered on a bit, shard is flipped over ...

...to hammer on some more, because that's how you stick metal together.
Everyone knows that!

fade/overlay of steam from quenching sequence (omitted here) to tempered blade

Voila! a dripping Anduril, already smooth, and perfectly grooved despite hammering
and annealing, shiny and mystically free of firescale without any boring polishing!
 

(--Hey, that's how they do it onstage in Wagner...it's gotta be right, right?)