Skybuilders' Hammer

Taken all the way down to base materials, one Skybuilders' Hammer is 2 crafting steps deep and needs 1 intermediate — Dark Chestnut Lumber ×1 — which resolves to 3 distinct raw materials totalling 17 units, plus 10 crystals.

That bill outweighs 7,161 of the 13,602 recipes tracked here and 757 of the 1,932 Blacksmith ones, and 4,464 recipes nest deeper.

Only 6 of those crystals go into the final step; the other 4 are burned by the intermediates, so the real crystal cost is 4 Fire Crystal, 4 Wind Crystal and 2 Earth Crystal.

The chain crosses two disciplines — Blacksmith to Lv 60 and Carpenter to Lv 54 — 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, Dark Chestnut Lumber has the widest use: 74 recipes call for it, spanning six of the eight crafting classes.