I may have been too ambitious with one property of my advanced Mesoamerican civilisation. The very summarised background (which you can take as given; don't frame challenge this) is that after a wise king in Teotihuacan invented a writing system that was usable by the general populace, and started sailing the Caribbean for guano, both the population and its literacy rate boomed. Over time bureaucratic realms replaced tribute empires, and by the 13th century Mesoamerica had become a second China on the world stage; a developed society of a hundred million people. Contact with Europe was eventually established but because this time plagues went in both directions, and the Mesoamericans were better equipped to fight any invaders, both continents survived with their societies largely intact.

Here's the thing: I want to maintain a number of changes from Europe, and probably the most consequential one is probably the continued lack of iron. My Mesoamericans can have copper and gold, for jewels and currency, and a bit of bronze is possible for specialised use (there was some tin in Mexico); but no iron except for the few trinkets they traded from people in the Pacific Northwest.

So what does the absence of iron and steel entail? For many applications of iron there are alternatives: woodworking joints instead of nails, a [macuahuitl](https://en.wikipedia.org/wiki/Macuahuitl) instead of a sword, bronze for precise tools. [This page](https://www.reddit.com/r/explainlikeimfive/comments/1warvr/eli5how_exactly_does_iron_beat_bronze/cf08emd/) even suggests that bronze is not that much softer than iron but just easier to produce because you only need the one kind of ore. The absence of steel might be more consequential, but right now I cannot think of a place where you *really* need the hardness of steel in the middle ages; except in blades, and blades only need to be super-hard in order to not be broken by other blades or on hardened armour. If nobody has steel, then that arms race doesn't exist, to my understanding at least.

What else does the lack of iron entail? Cannons are going to be hard but this society can do without gunpowder entirely. Having to use wooden/stone/bronze ploughshares would make agriculture a bit more inconvenient, but not debilitatingly so, I hope.

So I am looking for **the most radical and consequential changes that a lack of iron would effect on an otherwise High Medieval society**. I hope they are not too debilitating, preventing a China-like state from even existing.

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Specifically, the China/Europe-in-the-year-1250-like properties I want are:

* High population
* High degree of urbanisation
* Bureaucratic government
* Enough food surplus to allow for expenses on sciences, arts, a standing army, etc.

Note that I'm not asking for any specific Inventions like clockwork, printing press, etc, unless any of those happen to be crucial for any of the above items. I really want a subcontinent as developed as 1250s Europe, with expansive private commercial enterprises, with many different cities and places where people could pursue arts and sciences. And preferably with a bureaucratic government rather than a hereditary one.

Does a lack of iron stand in the way of any of those? If so, to what degree, and are there creative ways around it?