back to article Find pushes back birth of Europe's steel hardware to about 3,000 years ago

It's time to update the history books again. A group of researchers in Germany have shown that steel tools were being used in the Iberian peninsula at least as long ago as 900 BCE – far earlier than it was believed knowledge of the metal alloy had made its way to the region. The team, led by University of Freiburg …

  1. Potemkine! Silver badge
    Pint

    <Spoke>Fascinating</Spoke>

    1. Joe W Silver badge
      Pint

      Extremely!

      I always find this combination extremely intersting, and probably for the researchers a lot of fun.

  2. Anonymous Coward
    Anonymous Coward

    People move around shocker !

    The key point about even a single out of place artefact is it speaks to an entire infrastructure that must - simply must - have existed. And for that infrastructure to exist, certain other key elements must have been in place.

    The fact that British "dark ages" finds - quite aside from the stunning quality - that contain minerals that can only have come from India means there must have been a trading path from there to here. That was established enough for people to use regularly. Meaning overall peaceful times.

    1. steelpillow Silver badge

      Re: People move around shocker !

      Indeed. And given the global transport infrastructure steadily being revealed by such finds, with its origins dating back right back into the mesolithic, if not the palaeolothic - even Neanderthals owned traded goods from cultures hundreds of miles away - the idea that iron and steel were independently discovered over and over again is absurdly untenable.

      1. TeeCee Gold badge
        Alien

        Re: People move around shocker !

        That factual information won't stop one of the Erich von Daniken types writing a whole book around this though.

      2. Elongated Muskrat Silver badge

        Re: People move around shocker !

        I think we can be pretty sure that even if the goods were traded, the skills to produce them would not have been given away. No trader is going to give away the secret to producing their trade goods to their customers.

        Did you read the bit in the article that said there was evidence that the steel tools were produced locally, in the Iberian Peninsular?

        Whilst there's a possibility that people who already had the skills to produce steel may have moved about a bit, the sort of infrastructure needed to produce such alloys is unlikely to have moved with them, and I doubt steel-makers from China or India would have been travelling with traders to go and live in Portugal.

        1. Al fazed
          Happy

          Re: People move around shocker !

          In the olden days, I believe it was customary for an invading army to preserve for export, scribes, metal workers, ceramists, healers et al.

          The producers did not give away their secret formulas, they were kidnapped and had new masters, if they were lucky. Otherwise, what they knew locally died out with their family during the take over.

          ALF

          1. Elongated Muskrat Silver badge

            Re: People move around shocker !

            I don't recall ever reading about the bit where raiders from the Iberian peninsular attacked India (the nearest place making Steel at the time), captured large bits of territory and stole their technologies. At least not until relatively modern times, when the Portuguese colonised parts of the Indian West coast.

            If steel arrived as trade goods, it would have almost certainly have been via itinerant traders, who themselves would not have known the secrets of its production (a trader is not a smelter). Bear in mind that steel is produced using blast furnaces, a considerable step up from simple smelting; it requires high temperatures, a source of high-purity carbon, limestone, and the technologies to pump air through the furnace to get it hot enough. The technology to do this today is not all that different from when it was discovered. An early iron-age trader isn't going to have one of those on the back of his coracle.

            1. Professor Woozle

              Re: People move around shocker !

              Sorry, but that's not the case - you do not need a blast furnace to produce steel, all it needs is a higher charcoal to ore ratio in a simple smelting hearth so there's more carbon monoxide available in the reducing zone to go into the iron, and the iron ore to not contain certain impurities, principally phosphorus.

              The finding of this paper is also not as ground-breaking as they're making out, IIRC (from my university days three decades ago) the earliest dated iron artefacts in the British Isles (of similar date to these Iberian ones) had steel cutting edges that had been welded on to a softer iron back, and they had also been quenched and tempered to give the edge the optimum combination of hardness and toughness as a working tool. What it's showing is that when the technology of iron and steel working reached the western edges of Europe, it was a mature technology. What's harder to tell is whether objects being made elsewhere were traded in, craftsmen from areas where the technology was already established were moving in, or local craftsmen were acquiring the knowledge. Given we're actually talking about a range of some centuries, a combination of all of the above is entirely possible, and all of them are difficult (though not impossible) to definitively evidence in the archaeological record.

              1. John Brown (no body) Silver badge

                Re: People move around shocker !

                Agreed. The bit of the article that states "The bottom line is that steel was being used in Western Europe without any external influence bringing it to the region," seems to be a bit of a leap and/or a great assumption. It is absolutely likely that steel was invented multiple times in multiple locations, but nothing in the article makes the Iberians steel definitely a local invention. Trade and knowledge transfer has happened for a long as humans have "owned" stuff and that far back in time it's nigh on impossible to definitively state if something was invented locally or the knowledge was imported.

                And, of course, it IS interesting and valuable research, pushing back the dates of steel production and usage in that area and helping us understand a little more of the history of humanity.

            2. Lars Silver badge
              Happy

              Re: People move around shocker !

              "An early iron-age trader isn't going to have one of those on the back of his coracle."

              Yes I agree with that, but any stone age kid knew that if you blow on it too hard it will blow out, and papa will get angry, but if you blow on it just right it will start burning and everybody is happy, because that is how we made fire. Some seem to think this was invented only once and then that invention was just stolen and copied for the rest of the world.

              As for metals, we kept on burning, and keeping fire in the same place surrounded by stone of different types for thousands of years and eventually among those ashes people somewhere found interesting stuff, metals like copper.

              Working out that different stones might contain different stuff is not that hard to grasp and getting the idea of applying more heat is not that hard to understand and achieve either.

              We are simply very good at underestimating our ancestors, or to put it another way we are very good at overestimating ourselves, and when it gets really annoying we introduce the space guys and gods.

              This reminds me of a movie about us in the stone age, out looking to find fire to bring home.

              And because it was long ago we walked like having arthritis, clumsy and slow, also stupid enough not to understand water wasn't good for fire.

              Such a bloody stupid assumption, it's like going to the third world expecting kids to be slower and more clumsy than in some more modern western suburb.

              1. Elongated Muskrat Silver badge

                Re: People move around shocker !

                As for metals, we kept on burning, and keeping fire in the same place surrounded by stone of different types for thousands of years and eventually among those ashes people somewhere found interesting stuff, metals like copper.

                What you are describing is smelting, first used to make copper and bronze, then iron. IIRC, steel production requires much higher temperatures than you find in a typical wood fire, hence the invention of the blast furnace. If I remember rightly, these could be made to work with charcoal, but the ones we have nowadays run on coked coal.

                As the other poster above pointed out, there could have been some steel production without blast furnaces, but again, IIRC, this relies on the exact right conditions in the really hot bit of a fire and produces relatively small amounts of steel. Enough to maybe put an edge on a cutting blade, but hardly a means of production in quantity.

                1. Lars Silver badge
                  Coat

                  Re: People move around shocker !

                  @Elongated Muskrat

                  I think we can assume there are quality differences in the steel produced long ago and now and in between.

                  The first tool we had to transform something was fire so it's not surprising that we talk about the bronze age followed by the iron age.

                  The Wikipedia has some of ancient steel production in different parts of the world like this:

                  "In Sri Lanka, this early steel-making method employed a unique wind furnace, driven by the monsoon winds, capable of producing high-carbon steel."

                  https://en.wikipedia.org/wiki/Steel#History

        2. Al fazed
          Happy

          Re: People move around shocker !

          No one in their right mind is going to carry from coast to coast great armfuls of iron ore and limestone. This sort of shit is a modern affliction.

          I assume that in the days before international transport, flint knappers knapped flint where they found it, or where it was dug it from the earth, ie; Dorset, etc. Clay does not carry well when wet and it is damned heavy, so potters of yore dug pot holes where ever they could find clay emanating from the ground. They did not have the machinery to mine it like it is produced to day. No generally speaking "they" did not carry the raw materials with them unless the material was small and light in weight.

          Some enterpising Romans, Greeks, Egyptians etc, did cart stone and timber thousands of miles before working it, but this was not a gereral practice, just something folks managed to do over thousands of years of human history. Presilli Blue stones carted to Wiltshire to build Stonehenge, I believe is not something done every day.

          ALF

          1. Wellyboot Silver badge

            Re: People move around shocker !

            You're right, bulk transport of heavy raw materials across countries is quite recent, however, long distance transport was well established across the world 5,000+ years ago. The main method was rafts, barges & boats on rivers* and along coastlines, Finished products could potentially travel thousands of miles from the lucky places where all the components were close together.

            * Digging canals for when the rivers didn't go where you needed them was a major leap forward in accessibility.

          2. Anonymous Coward
            Anonymous Coward

            Re: People move around shocker !

            Where I live, they would knock up adze and axe blanks from fine grained argillite at/near the quarries or outcrops it was found at.

            This reduced the weight for shipping, without adding too much labour content.

            These were transported up to 2000km, and then knapped and ground to final shape elsewhere, presumably by users with plenty of time on their hands for the long slow part of the job.

        3. JohnTill123

          Re: People move around shocker !

          Why wouldn't steel-makers from China or India want to live in Portugal? The wine is SO much better!

          Seriously, though. If there are steel-makers in a location where there is a surfeit of such skills, they would do well to emigrate and find a place where exercising their skills will be profitable. So it could be "voluntary emigration" of people looking for economic opportunities. Or it could be a diaspora of steel-makers caused by warfare and conquest: The world experienced a LOT of violence around the time that steel-making was discovered.

          The "infrastructure" used to make steel back then really just required a source of iron ore, appropriate fuel (charcoal, wood) and leather, clay and stones to build a hearth/forge with a bellows.

          Ref:

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

          http://dtrinkle.matse.illinois.edu/MatSE584/articles/steel_greece_rome/steel_in_ancient_greece_an.html

          1. Elongated Muskrat Silver badge

            Re: People move around shocker !

            It's a bit more complex than iron ore + carbon + heat (that's how you smelt iron). To produce steel, you need higher temperatures, and limestone which reacts with the impurities such as sulphur in the ore and fuel. The "infrastructure" to produce steel is a "hearth/forge with bellows" and a means to prepare and supply the "ingredients" of steel. You could probably manage this with neolithic materials, but you'd essentially be building a blast furnace, and there's pretty strong evidence to suggest that was invented around two thousand years later.

            That doesn't mean individuals couldn't have invented their own version of this, but, again, it doesn't look like that technology became well known or widespread until the invention of the blast furnace, do it's more of a "didn't" rather than a "couldn't". Or even "did, but didn't spread" as this article suggests.

            1. Professor Woozle

              The practicalities and science of steelmaking ( was - Re: People move around shocker ! )

              Sorry, but that's not the case - in a bloomery furnace, what determines the carbon content of the raw iron produced (the bloom) is the level of excess of carbon monoxide over and above that required to react with the iron oxide to form carbon dioxide and iron. If you increase the rate of air flow and the amount of fuel going in, you will raise the temperature and amount of carbon monoxide in the reaction zone to the point where enough carbon has gone into the iron to lower its melting point to the furnance temperature, resulting in cast iron - not steel, note, but cast iron which is higher in carbon and brittle. The critical temperature at which carbon can begin to diffuse into iron is a little over 700 degrees C, where the crystal structure of iron changes (the Austenitic point) - the rate of diffusion will increase as the temperature gets higher, until eventually you hit the point where the increased carbon content has lowered the melting point of the iron to the ambient temperature of the furnance, and you get cast iron instead of hypereutectoid steel.

              There are three routes to getting a steel with a carbon content suitable for making tools and weapons (generally 0.5 to 1%). Firstly, there's direct production in the bloomery furnance by using a higher fuel to ore ratio, which produces steel in the solid state without it being molten - a good example of this is the traditional Japanese smelting process, where the blooms would include both softer iron and harder steel and the smelters/smiths could recognise which was which. Secondly, there's cementation, where bars of iron are packed into a sealed container with charcoal and heated for an extended period - the Wootz process is an example of this, though they got the furnance hot enough that the resultant steel melted within its sealed container. Thirdly, there's decarburisation, where molten cast iron has a blast of air put through or over it to burn out the carbon until it reaches the desired content - the Bessemer converter is the classic example of this, but there's evidence that suggests tool steels may have been made in antiquity by decarburising cast iron.

              Steelmaking technology was it seems widely known in antiquity, going by the amount that's been found. Given it was an expensive (and recyclable) material, it's quite likely under-represented in the archaeological record as it was always more expensive than regular wrought iron (which in turn wasn't a cheap commodity in the past), and so would have been more likely to get re-used. From what's known from historical writings, there probably was a strong element of craft secret and "do this thing that grandad told us to" about it, but around the world, every iron-using culture seems to have had some way of making "the tough stuff" and working it into a usable tool or weapon.

              As for blast furnaces, they're pretty much the same as a bloomery furnace being at the core a shaft built out of refractory material with a source of air blast at the base and an open top where you put the ore and fuel in. The only real difference is that the blast furnace has a stronger blast of air going in (hence its name), burning more fuel to given the conditions that will result in molten iron.

              I'll give you one guess what I did my dissertation on at university all those years ago...

              1. Elongated Muskrat Silver badge

                Re: The practicalities and science of steelmaking ( was - People move around shocker ! )

                It's my understanding (and I'm more than willing to defer to someone with greater knowledge) that steel isn't just an alloy of iron and carbon, but that its manufacture also involves removing the impurities found in pig iron, especially sulphur, which makes steel brittle, and pretty much useless. It might be that high-purity iron ores combined with a decent sulphur-free carbon source would achieve this, but ancient peoples wouldn't be expected to know what is in their iron ore (just that it's this specific orange rock), and both coal and charcoal can contain high levels of sulphur depending on their source.

                Please do correct me if I've got this wrong, I'm going from memory of what I was taught many years ago in undergraduate chemistry classes...

                1. Professor Woozle

                  Re: The practicalities and science of steelmaking ( was - People move around shocker ! )

                  I can see why we're at odds over this now, which is a good start! What you were taught isn't wrong, but it's really only applicable to post-19th century steel production. There have been two major technological shifts (in European steelmaking) since antiquity, firstly the move away from the bloomery furnace to the blast furnance in the 16th and 17th centuries, and secondly the move towards alloyed steels from the mid-19th century onwards as improved scientific analysis gave rise to steels that were optimised for particular jobs.

                  However, steel is in its strict definition, the alloy of iron and carbon and if other elements are there by design, then it's an alloy steel. Although some steels in the past did have trace elements in them (Wootz, for example has a small amount of Vanadium in it, which does some interesting things with the crystal structure), it wasn't intentional, it was a by-product of the ore used.

                  The hotter temperature of blast furnances does change what goes into the iron and what goes into the slag; some silicon can get into blast furnace iron while the use of limestone is to improve the yield by providing calcium to preferentially combine with the silicon and go into the slag. In bloomery smelting, the temperature isn't high enough for that and instead, any silicon combines with some of the iron to form a liquid iron silicate slag. That's part of the reason for the adoption of the blast furnace over the bloomery, in that you recovered more of the iron from your ore; you could also resmelt bloomery slag and recover the iron from that.

                  As for Sulphur, yes it's something you don't want in iron as it causes embrittlement at high temperatures, and it falls into bits when you try and forge it! That's why charcoal was generally used for smelting and smithing until the industrial revolution as any Sulphur present in the wood it was made from tends to disappear as Sulphur Dioxide during the charcoal burning process. There are some places where coal was used in antiquity, but those are places that happened to have easily-dug sources of coal with minimal Sulphur content. It wasn't until the coking process was perfected (basically doing the same thing as you do to wood in charcoal making, burning it just enough to get rid of unwanted impurities and leaving mostly carbon) that fossil-fuel based iron and steelmaking took off, as it freed the ironmasters from the constraint of available sources of wood to make charcoal from. Although it's often repeated that ironmakers were responsible for destroying a lot of woodland, the reverse is true - while charcoal was needed, they were buying or renting woodlands to secure their fuel supply, the shift to coke made the woods less valuable and prompted landowners to clear them and turn the land over to agriculture where that was viable.

        4. Spherical Cow Silver badge

          Re: People move around shocker !

          "Did you read the bit in the article that said there was evidence that the steel tools were produced locally, in the Iberian Peninsular?"

          The article does not mention any evidence the steel tools were produced locally, all it says is the researchers hypothesised the tools were made locally.

          The simplest explanation is trade.

          1. Intractable Potsherd

            Re: People move around shocker !

            That's interesting - I don't regard trade as the simplest explanation by a long chalk. Local production seems much more likely (subject to the right materials being available).

            1. Professor Woozle

              Re: People move around shocker !

              I disagree about local production being the most likely explanation and this is why. What we see with the emergence of iron on the Atlantic seaboard in the LBA is artefacts that are not only made of iron, but also include steel that's been quenched and tempered. There are several technological leaps here from bronze working, all of which were by that time well established in the eastern Mediterranean and Anatolia. Bronze was still in widespread use, so copper and tin deposits like those in Britain/Ireland and Spain were being worked and traded into the Mediterranean. If you have traders from either place going to the other, or a chain of trade going on, then would you not likely see the new "wonder metal" being traded westwards as the copper and tin was traded east?

              There will have been a point where iron and steel making did start on the Atlantic seaboard, but... first of all, you have the difference in bloomery iron making that what comes out of the furnance is not a castable liquid, but a grotty-looking sponge of iron and slag, that you then need to keep heating and beating until most of the slag has gone and you have a bar of iron you can make something out of. Secondly, you have to know that some bits of this iron are harder than others, and if you take those, drop them into water while they're red hot, then gently re-heat them until certain colours show, you get something that's a lot harder than regular iron but doesn't shatter (which it will if you hit it straight after dropping it into water). Finally, you need to be able to forge-weld that harder stuff onto regular iron, and there's a very narrow temperature range just below white hot at which that can be done otherwise your precious hard stuff turns into a sparkler and burns away, or the weld doesn't take and the cutting edge falls off your tool/weapon when you try to use it.

              Given all of that, for the very earliest iron artefacts on the western fringes of Europe which show that they were steeled and quenched and tempered, I think there are rather fewer assumptions involed in them having been traded in.

              1. Elongated Muskrat Silver badge

                Re: People move around shocker !

                The article does mention that the researchers had a reason for thinking it was locally produced, but didn't say what that was. It could be the particular location was remote and thus not on trade routes, or the quantity of steel required for the number of stone carvings would have made it unlikely that valuable trade goods would be used for chipping rocks?

                In any case, it is all fascinating stuff.

      3. Al fazed
        Happy

        Re: People move around shocker !

        In the Ashmolean museam in Oxford, there are examples of "Imperial" ceramic wares covered with a beautiful red glaze.

        In the past, this red glaze was referred to in order to prove an unbroken line of Imperial rule in China.

        However, recent examination of these artifacts glazes has shown that the glazes were in fact made from three independant formulas, each glaze having been re-invented after breaks in production of several hundred years. Source locations of the material used in the glazes had apparently been dug in three different regions, in different periods of China's long history of Imperial rule.

        ALF

      4. Lars Silver badge
        Happy

        Re: People move around shocker !

        @steelpillow

        "independently discovered over and over again is absurdly untenable.".

        Why would that be untenable. I find it more untenable that every invention was invented only once and then, as the article writes, - " ,, knowledge of the metal had made its way to the region".

        We know of lots of more modern invention that were invented at the same time in several countries.

        Any suggestion where and when in the world the first shoe and the first boat was invented.

        But I also think we have been roaming the world a lot and for a long time.

        And I don't think kids born 50.000 years ago were less intelligent than kids born today.

        (at least I don't believe a modern crocodile to be more intelligent than one born 50.000 years ago.)

      5. steelpillow Silver badge
        Facepalm

        Re: People move around shocker !

        I hate to pour could water on some of the grumpy parades here, but it is as well to bear in mind that these technologies took hundreds, sometimes thousands, of years to mature and move around the globe. The idea that medieval-style guilds could prevent the technology from leaking out over such timescales is perfectly ridiculous. Of course the stuff came to be made wherever the raw materials were handy.

        Case in point: the Graeco-Roman lifelike style of statuary appeared in China some short while after Alexander the Great passed away, not because they reinvented lifelike style but because they hired Graeco-Roman masons to come over and carve stuff for them. And that migration took only a few decades at most.

        Some folks here need to fsck their ideas for data corruption.

      6. that one in the corner Silver badge

        Re: People move around shocker !

        > were independently discovered over and over again is absurdly untenable.

        We don't really need to argue over this and that bit of history to know that is a dubious statement.

        This is El Reg, where a major part of the commentard's day is spent berating the youth for reinventing the wheel. Again. Just like yesterday. And this in an age when we have plenty of reference materials to hand.

    2. DJO Silver badge

      Re: People move around shocker !

      In the early bronze age Greek traders went north to what they knew as the "Tin Islands" to trade for the Tin needed to make bronze. The main trading port there was a settlement that later became known as Tintagel.

      The trade route between Britain and at least as far south as the Mediterranean was well established 2000 years before the "Dark Ages". The "Dark Ages" are called "Dark" because of the lack of documentation as to what was going on at the time. All that means is there was no writing on durable materials that has survived, it does not mean there was nothing happening.

      1. richdin

        Re: People move around shocker !

        The Jewish calendar is currently year 5783, while the Chinese calendar started only 4660 years ago. The 1123 years before Chinese food was invented is called the Dark Ages.

    3. Al fazed
      Happy

      Re: People move around shocker !

      A friend recently went to India with some tin he had collected in Cornwall. In a market in Calcutta he found someone to buy his tin. The purchaser pointed out that my friend was the latest person to bring tin from Cornwall to Calcutta where they produce pewter using the Cornish tin. Apparently the Phoenecians were amongst the first traders to take tin from Cornwall to Calcutta.

      ALF

  3. Anonymous Coward
    Thumb Up

    Nice Work

    It's nice to see researchers upending established archaeological timelines like this. The past is obviously more complicated than history books would have it.

    As for the Romans - it appears that people all over were happy making and using steel objects as tools, but it took the Romans to take the step of spreading steel use literally at the pont of a sword.

  4. disgruntled yank

    Also

    It seems to me that some philologists take one or two epithets attached to "iron" in Homer to mean steel. I don't know what sort of interpretive tradition might be behind that. But the Homeric epics were put together something around 2800 years ago, weren't they?

  5. Doctor Syntax Silver badge

    If it's known how to produce iron in any form from ore then it's likely that iron-working sites would of the period would have been discovered and the Early Iron Age would have been pushed back to that period. I take it that no such sites were known. That raises the possibility that this was derived from meteoric iron. How close is the carbon content of meteoric iron to that of steel?

    1. DJO Silver badge

      Iron meteorites contain 0 to 20 ppm of carbon. The giveaway for meteorite iron is the nickel content.

      1. Elongated Muskrat Silver badge

        The isotopic composition of the carbon would also be different. Biological processes on earth deplete carbon-13 due to the primary kinetic isotope effect, the upshot of which is that extraterrestrial carbon sources are relatively enriched in 13C compared to terrestrial sources (such as coal or charcoal) and this stands out like a sore thumb.

    2. Charlie Clark Silver badge

      Absence of local production and of steel artefacts do suggest transitory use at best. The logic "this can only have been made by steel, they must have had steel, they must have known how to make steel" seems more than a little shaky to me. In fact, it's close to a strawman. What finds generally tell us is that our current theories and assumptions are insufficient to explain them.

      1. Rol

        Thankfully for the archaeologists trying to date non-organic materials, the spade was not invented until 1760 by Spear & Jackson. And so all manner of things were just discarded on the ground, rather than hidden in a hastily dug out hole, thus adding several hundred years to their age.

    3. Al fazed
      Happy

      Known just not shouted about

      Fact, in South Wales archeologists working near Neath discovered a previously unknown iron smelting facility which had been burried beneath the known and much later, Middle Ages iron smelting facility assocaited with the Abbey.

      Upon further investigation it was discovered that the original facility had been visited by the Romans, NOT built by them.

      I am not sure of the final outcome of the research, but I am sure that there is some paper written about steel production in South Wales prior to the Roman invasion of Britain.

      ALF

      1. Elongated Muskrat Silver badge

        Re: Known just not shouted about

        Be careful not to get iron smelting (heating iron ore and carbon together to get molten iron and carbon dioxide), which can be done at relatively modest temperatures (it was demonstrated to us at school using a charcoal block, iron oxide and a Bunsen burner), with steel production. There are a couple of important differences between iron and steel; firstly the carbon content (much higher in steel), and secondly the level of impurities such as sulphur, phosphorus and silicon, which are much, much lower in steel.

        That's not to say that they couldn't have been making steel in Neath, but not in an iron smelter.

    4. Wellyboot Silver badge

      The Carbon content of meteoric Iron is almost irrelevant, the charcoal used to smelt or forge it would add plenty into the mix.

      Once you can smelt iron the biggest hurdle to steel making is keeping other impurities out.

  6. anonymous boring coward Silver badge

    You misspelled "librarians".

    1. Spherical Cow Silver badge
      Joke

      Bibliotecários, Shirley?

    2. John Brown (no body) Silver badge
  7. rcw88

    When is steel not steel?

    When the carbon content of iron is over 1% its not steel any more, not even close. Anything more than that and you are in trouble, mild steel is about 0.1 - 0.3% carbon, proper tool steels are iron with a bit of carbon plus a load of alloying extras, e.g chrome, vanadium, manganese. All this takes a LOT of heat to get them to even melt, let alone create a usable alloy tool steel.

    Iron + a lot of carbon if melted without purification and poured simply results in cast iron, with carbon flakes dispersed in all the awkward places that make it wonderfully brittle. Getting from cast iron to something usable requires a capable forge, a hammer and an expert forgemaster - folding and beating out the impurities, alternated with reheating to bright red, rinse and repeat until it stops sparking when hit. This is wrought iron, not steel, lovely and tough, with the metals grains aligned in the direction its been rolled or hammered in.

    Modern steels are made in an electric arc furnace after starting with pig iron, adding limestone and other materials to get the impurities into the dross on the surface, its a spectacular process.

    A carbon tool steel can be hardened and softened at will, after shaping, heat to cherry red and plunge into something much colder [water or oil are the normal choices], then polish the surface to a shine, heat from the blunt end and watch the oxidation colours travel down the object, start with pale straw and finish with deep blue, this is the process of tempering a high carbon tool steel [high being a relative, not absolute term].

    So its fascinating to read that the iron / steel age is even older than previously thought, I guess nobody will be allowed to cut one of the finds in half so it can be sectioned, polished and etched to look at the metal structure, then put into a mass spectrometer to find out what the composition is...

    1. captain veg Silver badge

      Re: When is steel not steel?

      I don't know why, but my post pointing out that that Carbon is not a metal was rejected. That's pretty much all it said. Weird.

      -A.

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