I like to ask “what if” questions.

I’ve been noticing that the long dominance of iron & steel as the material of choice has been taking a battering lately. Steel nails are being replaced by glue. Sheet and tube steel is being replaced by aluminium sections and sometimes structural plastic. It may even be possible to build a complete computer without any iron in the end product – gold, copper, silicon, fibreboard, glass, aluminium yes. As I look around my lounge room, a lot of what I see is not made of iron.

So what would the world look like today if there had been no iron age? Would we have been able to overcome the lack of steel in heavy industry equipment? Would certain technologies have failed to develop, while others developed faster? Or would we still be stuck back in the bronze age without modern technology?

These aren’t questions that can be answered definitively, particularly because the bronze age lasted much longer in SE Asia than in Europe. And SE Asia didn’t progress much beyond the bronze age until contact with Europeans.

In terms of history, Iron became the material of choice shortly before 0 BC. Before that, materials that had been developed were dominated by wood, stone, gold, skins, flint, brick, pottery, plant fibres, copper, glass, glue, tin, bronze, cement and paper.

Iron/steel was definitely the material of choice in Europe then until about 1900 AD. During that period, the only new materials of note were refractories and rubber. Advances in iron technology during that period included cast iron about 1000 AD, carbon steels about 1810, wrought iron about 1820 and alloy steels about 1840.

Iron rusts. It is also strong. Early uses included spearheads, knives, axes, swords, sheet armour and chain mail. Military uses. No great loss if they were never developed.

It is difficult to imagine a modern railway without iron. Ditto a lot of mining equipment: trucks, ore crushers, oil rigs, tanks containing chemicals. What influence would the lack of an iron age have on mining?

One important property of materials is the need to manipulate it while it is soft and then harden it later. Quenching and tempering started to become common in about the 1500s. This better allowed the use of iron/steel to be used as a tool for shaping iron/steel.

Last time I checked, iron-based alloys are still the strongest bulk materials on the planet. Though titanium-based alloys, nickel-based alloys, and carbon-fibre-reinforced-plastic are starting to get close.

It is steel that has given us concrete reinforcement bars, skyscrapers, and long-span bridges. In the past 50 years, concrete is slowly replacing steel in smaller civil engineering projects.

So, how would the world have developed without an iron age?

I can envisage an earlier use of glass fibre and mineral fibre (eg. asbestos) as a concrete reinforcement. An earlier development of modern glues. An earlier use of nickel and titanium alloys. An early use of carbon fibre was in 1879, the carbon fibre technology could have started off then rather than waiting until 1958. Perhaps an earlier development of aluminium production by electrolysis because the most necessary components: copper wires, carbon electrodes and refractories, do not rely on iron.

In the early industrial age, steam engines were often made of brass/bronze rather than iron/steel. If bulk steel wasn’t around then a push could have been made to develop stronger and springier copper alloys earlier … In particular https://en.wikipedia.org/wiki/Beryllium_copper, which has a strength up to 1,400 MPa, good weldability and machining properties, and can be made with a hardness similar to that of steel.

Another technology advance I see that could perhaps have occurred sooner is the embedding of ceramic into the surface layers of soft metals, notably aluminium and copper based alloys, to greatly increase their hardness. This wasn’t necessary in an iron-based manufacturing. Hard ceramics include alumina available at low cost as a byproduct of aluminium production.

Putting it together. Without the ready availability of cheap iron/steel, large projects would have had to be considerably reduced in size. This includes skyscrapers, mining and transport equipment, bridges. But small items could have advanced faster through the need for strong and hard non-ferrous materials. Electricity, glass fibre, carbon fibre could have been available earlier.

A remaining question, however, is whether oil/gas mining would have been possible at all without iron/steel? Plastics can be manufactured from plant materials (eg. viscose) and coal rather than oil/gas, but it is far easier to manufacture plastics from oil/gas.

So, would the lack of an iron/steel age have so severely hampered technological development that it stopped the development of modern technology? Or would the loss of iron/steel merely shift the technology balance towards smaller scale development?

PS. I’m a big fan of the idea of using manganese alloys as a replacement for iron alloys. Deep sea manganese, if mined, would be available at very low cost, and manganese is intrinsically harder and stronger than iron.

Without being a chemist or materials engineer, my gut feeling is that humanity would still progress, with some delays or missing tech.

From what I can think, iron was mostly used structurally. So we can still have all the things we have now more or less, but built out of different materials. You could have wooden cars for example, with aluminium engines.

E.g. https://en.wikipedia.org/wiki/Aluminum_internal_combustion_engine

It’s an interesting thought experiment, but at some point I’d have to ask, is iron missing from the periodic table, or did humans just not discover it? Or we did discover it, but we just have some sort of religious conviction against using it, or what?

Kothos said:

Without being a chemist or materials engineer, my gut feeling is that humanity would still progress, with some delays or missing tech.

From what I can think, iron was mostly used structurally. So we can still have all the things we have now more or less, but built out of different materials. You could have wooden cars for example, with aluminium engines.

E.g. https://en.wikipedia.org/wiki/Aluminum_internal_combustion_engine

It’s an interesting thought experiment, but at some point I’d have to ask, is iron missing from the periodic table, or did humans just not discover it? Or we did discover it, but we just have some sort of religious conviction against using it, or what?

Wasn’t some of the first iron meteoric in origin

Cymek said:

Wasn’t some of the first iron meteoric in origin

That sounds right. That stuff didn’t have to be smelted from ore.

Kothos said:

Cymek said:

Wasn’t some of the first iron meteoric in origin

That sounds right. That stuff didn’t have to be smelted from ore.

Yes, that’s what I remember reading

Cymek said:

Kothos said:

Cymek said:

Wasn’t some of the first iron meteoric in origin

That sounds right. That stuff didn’t have to be smelted from ore.

Yes, that’s what I remember reading

There is a single meteorite in Greenland, about 60 tonnes worth, that was the source for most of the iron used in Greenland and the Canadian Arctic until the modern era.

dv said:

Cymek said:

Kothos said:

That sounds right. That stuff didn’t have to be smelted from ore.

Yes, that’s what I remember reading

There is a single meteorite in Greenland, about 60 tonnes worth, that was the source for most of the iron used in Greenland and the Canadian Arctic until the modern era.

Is there still iron in it or is it all used up now?

Kothos said:

dv said:

Cymek said:

Yes, that’s what I remember reading

There is a single meteorite in Greenland, about 60 tonnes worth, that was the source for most of the iron used in Greenland and the Canadian Arctic until the modern era.

Is there still iron in it or is it all used up now?

https://www.sciencedirect.com/science/article/abs/pii/104458039290112U

As an aside I doubt there was much aluminum produced before the advent of commercial electricity.
Maybe it was but by a different method, dunno.

Peak Warming Man said:

As an aside I doubt there was much aluminum produced before the advent of commercial electricity.
Maybe it was but by a different method, dunno.

Yeah it was expensive as fuck in the 19th century

dv said:

Peak Warming Man said:

As an aside I doubt there was much aluminum produced before the advent of commercial electricity.
Maybe it was but by a different method, dunno.

Yeah it was expensive as fuck in the 19th century

It’s interesting too because in another 100 years they’ll be thinking the same about electricity even today.

Peak Warming Man said:

As an aside I doubt there was much aluminum produced before the advent of commercial electricity.
Maybe it was but by a different method, dunno.

This is correct.

SCIENCE said:

dv said:

Peak Warming Man said:

As an aside I doubt there was much aluminum produced before the advent of commercial electricity.
Maybe it was but by a different method, dunno.

Yeah it was expensive as fuck in the 19th century

It’s interesting too because in another 100 years they’ll be thinking the same about electricity even today.

Either that or electricity will be known of only because of the campfire tales of the elders

Kothos said:

dv said:

Cymek said:

Yes, that’s what I remember reading

There is a single meteorite in Greenland, about 60 tonnes worth, that was the source for most of the iron used in Greenland and the Canadian Arctic until the modern era.

Is there still iron in it or is it all used up now?

Most of it still remains

dv said:

Peak Warming Man said:

As an aside I doubt there was much aluminum produced before the advent of commercial electricity.
Maybe it was but by a different method, dunno.

Yeah it was expensive as fuck in the 19th century

I suppose it’s similar to how antimatter is so expensive to produce now, will it be much easier and cheaper in a centuries time

dv said:

Peak Warming Man said:

As an aside I doubt there was much aluminum produced before the advent of commercial electricity.
Maybe it was but by a different method, dunno.

Yeah it was expensive as fuck in the 19th century

I suppose it’s similar to how antimatter is so expensive to produce now, will it be much easier and cheaper in a centuries time

roughbarked said:

Kothos said:

dv said:

There is a single meteorite in Greenland, about 60 tonnes worth, that was the source for most of the iron used in Greenland and the Canadian Arctic until the modern era.

Is there still iron in it or is it all used up now?

https://www.sciencedirect.com/science/article/abs/pii/104458039290112U

Plenty still left:

https://en.wikipedia.org/wiki/Cape_York_meteorite

Each material has a personality, it’s almost like dealing with living things. When aluminium replaced steel in scooters, the design changed radically. Ditto when rigid plastic replaced steel in shopping carts. When a corrugated iron roof is replaced by another material such as concrete tiles, the design is very different. No other material has the same personality.

The personality of iron-steel tends to be the following – thin, cheap, heavy, strong, made from very simple components (eg. pipe, sheet), welded. no creep, springy, hard, strength improved by quench and temper, somewhat heat resistant, needs rust protection. The combination of “thin” and “needs rust protection” sets up a paradox that has to be solved – thin sections rust faster. No other material has that combination of features.

Sometimes iron/steel is used in applications outside its normal personality, simply because there’s nothing better at the same cost. Three examples are: cast engine blocks, which needs very thorough machining after casting because iron/steel casting is so inaccurate; screws, which involve fiddly details that other metals handle more easily; and reinforcing rods for several reasons such as being tied rather than welded.

That said, the closest one-to-one substitutes for iron/steel for specific purposes would(?) be the following:

• Iron nails – replace with glue
• Screws (other than self-tapping) – brass
• Staples – brass or titanium
• Corrigated iron – aluminium or polycarbonate
• Cables (transient load eg. winch or mooring) – hemp or nylon
• Cables (permanent load eg. suspension bridge) – continuous carbon fibre or glass fibre
• I beams and columns – ?
• Large iron/steel bolts and rivets – ?
• C and Z purlins – aluminium
• Pins, safety pins, needles – brass or bone
• Water tanks – plastic or concrete
• Chemical tanks and food processing – nickel-chrome alloy
• Silos – concrete
• Thin section concrete reinforcement – fibreglass or mineral fibre
• Bulk concrete reinforcement – ?
• Post-tensioned concrete reinforcement – continuous carbon fibre or glass fibre
• Engine blocks & pistons – aluminium alloy
• Car wheels – aluminium alloy
• Car bodies – fibreglass or carbon fibre
• Drills – cobalt, nickel, titanium, metal-ceramic composite
• Handrails – wood
• Pipes (low pressure) – PVC
• Pipes (high pressure) – copper or titanium
• Armour – aramid or fibreglass
• Train rails – ?
• Piano strings – ?
• Scaffolding – bamboo

Relative metal and other costs, USD/kg
Mixed plastics 0.07
Recycled PET 0.25
Steel 0.6
Lead 2.1
Aluminium 2.4
Zinc 3.1
Copper 8.8
Titanium 9
Chromium 12
Nickel 26
Tin 26
Cobalt 34

Metal abundance. Leaving aside the highly reactive metals like sodium, the most common metals in turn, are:

• Aluminium, Iron, Magnesium, Titanium, Manganese, Strontium, Zirconium

So we should be looking at aluminium, magnesium, titanium and manganese first as low cost replacements for metallic iron.

Surely beams columns would be wood and concrete?