Iron Chair

Taken all the way down to base materials, one Iron Chair is 2 crafting steps deep and needs 3 intermediates — Chondrite Ingot ×6, Manganese Ingot ×6 and AR-Caean Velvet ×3 — which resolve to 5 distinct raw materials totalling 87 units, plus 136 crystals.

That bill outweighs 13,435 of the 13,602 recipes tracked here and 1,917 of the 1,932 Blacksmith ones, and 4,464 recipes nest deeper.

Only 16 of those crystals go into the final step; the other 120 are burned by the intermediates, so the real crystal cost is 104 Fire Crystal, 24 Lightning Crystal and 8 Earth Crystal.

The chain crosses two disciplines — Blacksmith to Lv 90 and Weaver to Lv 88 — so no single class can finish it unaided.

All 5 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, Chondrite Ingot has the widest use: 210 recipes call for it, spanning seven of the eight crafting classes.