Adamantite Rivets

Taken all the way down to base materials, one Adamantite Rivets is 2 crafting steps deep and needs 1 intermediate — Adamantite Nugget ×1 — which resolves to 2 distinct raw materials totalling 6 units, plus 10 crystals.

That bill outweighs 4,542 of the 13,602 recipes tracked here and 467 of the 1,932 Blacksmith ones, and 4,464 recipes nest deeper.

Only 5 of those crystals go into the final step; the other 5 are burned by the intermediates, so the real crystal cost is 10 Fire Crystal.

Every step is Blacksmith work, from a Lv 58 intermediate up to the Lv 58 finish, so one class covers the whole chain.

Both raw materials are gathered, and 2 of them are time-gated: Adamantite Ore (0:00, 2:00, 6:00, 10:00, 12:00, 14:00, 18:00, 22:00) and Darksteel Ore (1:00). The widest gap between consecutive opening times is 4 Eorzean hours, about 12 real-world minutes.

Adamantite Rivets is itself consumed by 25 further recipes, spanning four of the eight crafting classes.