Heavy Iron Armor

Taken all the way down to base materials, one Heavy Iron Armor is 3 crafting steps deep and needs 3 intermediates — Iron Plate ×4, Brass Ingot ×1 and Iron Ingot ×8 — which resolve to 3 distinct raw materials totalling 27 units, plus 17 crystals.

That bill outweighs 9,763 of the 13,602 recipes tracked here and 962 of the 1,441 Armorer ones, and 337 recipes nest deeper.

Only 4 of those crystals go into the final step; the other 13 are burned by the intermediates, so the real crystal cost is 8 Fire Shard, 6 Ice Shard, 2 Earth Shard and 1 other kind.

The chain crosses three disciplines — Armorer to Lv 25, Blacksmith to Lv 16 and Goldsmith to Lv 14 — 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, Iron Ingot has the widest use: 113 recipes call for it, spanning seven of the eight crafting classes.