Forged in Fire Season 5 Episode 4

Edged-weapon mastery is put to the test right away as four bladesmiths must forge a functional friction folder. Without knowing how their blades will be tested, each smith must find the critical junction where skill meets resiliency to produce a folding knife versatile enough to handle any test imaginable. Ultimately, only two smiths push through to the final round where they must recreate a Japanese trident called the Jumonji Yari.