Dwarven Mythril File

Taken all the way down to base materials, one Dwarven Mythril File is 3 crafting steps deep and needs 3 intermediates — Dwarven Mythril Ingot ×2, Dwarven Cotton ×1 and Dwarven Cotton Thread ×3 — which resolve to 3 distinct raw materials totalling 14 units, plus 35 crystals.

That bill outweighs 6,557 of the 13,602 recipes tracked here and 699 of the 1,932 Blacksmith ones, and 337 recipes nest deeper.

Only 14 of those crystals go into the final step; the other 21 are burned by the intermediates, so the real crystal cost is 21 Fire Crystal, 7 Earth Crystal and 7 Lightning Crystal.

The chain crosses two disciplines — Blacksmith to Lv 79 and Weaver to Lv 78 — so no single class can finish it unaided.

All 3 raw materials are gathered, and not one of their spots is timed, so nothing in the tree waits on the Eorzean clock.

Of the intermediates, Dwarven Mythril Ingot has the widest use: 168 recipes call for it, spanning seven of the eight crafting classes.