Iron Mortar

Taken all the way down to base materials, one Iron Mortar is 2 crafting steps deep and needs 2 intermediates — Iron Ingot ×2 and Elm Lumber ×1 — which resolve to 2 distinct raw materials totalling 9 units, plus 6 crystals.

That bill outweighs 5,492 of the 13,602 recipes tracked here and 597 of the 1,932 Blacksmith ones, and 4,464 recipes nest deeper.

Only 3 of those crystals go into the final step; the other 3 are burned by the intermediates, so the real crystal cost is 4 Fire Shard, 1 Earth Shard and 1 Wind Shard.

The chain crosses two disciplines — Blacksmith to Lv 21 and Carpenter to Lv 16 — so no single class can finish it unaided.

Both raw materials are gathered, and no spot for either 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.