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82-561: The location was originally the site of an Iron Age village which was removed during the 10th century to allow for the construction of the ring fortress. The fortress itself was likely constructed c. 980, and was later abandoned. Although the exact purpose of the fortress is unknown, the location is of significant strategic importance, as it overlooks a narrow strait of the Limfjord . In 2023, Aggersborg, along with four other ring fortresses in Denmark,

164-509: A tap or die , thread milling, single-point thread cutting, thread rolling, cold root rolling and forming, and thread grinding. A tap is used to cut a female thread on the inside surface of a pre-drilled hole, while a die cuts a male thread on a preformed cylindrical rod. Grinding uses an abrasive process to remove material from the workpiece. A grinding machine is a machine tool used for producing very fine finishes, making very light cuts, or high precision forms using an abrasive wheel as

246-490: A common method of deburring . Broaching is a machining operation used to cut keyways into shafts. Electron beam machining (EBM) is a machining process where high-velocity electrons are directed toward a work piece, creating heat and vaporizing the material. Ultrasonic machining uses ultrasonic vibrations to machine very hard or brittle materials. Welding is a fabrication process that joins materials, usually metals or thermoplastics , by causing coalescence . This

328-411: A different speed on the milling tool and varies in the amount of material that can be removed in one pass of the tool. Harder materials are usually milled at slower speeds with small amounts of material removed. Softer materials vary, but usually are milled with a high bit speed. The use of a milling machine adds costs that are factored into the manufacturing process. Each time the machine is used coolant

410-404: A lathe include candlestick holders, crankshafts , camshafts , and bearing mounts. Lathes have four main components: the bed, the headstock, the carriage, and the tailstock. The bed is a precise & very strong base which all of the other components rest upon for alignment. The headstock's spindle secures the workpiece with a chuck , whose jaws (usually three or four) are tightened around

492-461: A local development from Bronze Age culture. Another Iron Age nucleus considered to represent a local development is the Wessenstedt culture (800–600 BC). The bearers of this northern Iron Age culture were likely speakers of Germanic languages. The stage of development of this Germanic is not known, although Proto-Germanic has been proposed. The late phase of this period sees the beginnings of

574-438: A mineral-bearing rock , that require heat or some other process to liberate the metal. Another feature of gold is that it is workable as it is found, meaning that no technology beyond a stone hammer and anvil is needed to work the metal. This is a result of gold's properties of malleability and ductility . The earliest tools were stone, bone , wood , and sinew , all of which sufficed to work gold. At some unknown time,

656-424: A production shop, to today's 30000 RPM CNC auto-loading manufacturing cell producing jet turbines, grinding processes vary greatly. Grinders need to be very rigid machines to produce the required finish. Some grinders are even used to produce glass scales for positioning CNC machine axis. The common rule is the machines used to produce scales be 10 times more accurate than the machines the parts are produced for. In

738-410: A round hole. Drilling : Feeding the drill into the workpiece axially. Knurling : Uses a tool to produce a rough surface texture on the work piece. Frequently used to allow grip by hand on a metal part. Modern computer numerical control (CNC) lathes and (CNC) machining centres can do secondary operations like milling by using driven tools. When driven tools are used the work piece stops rotating and

820-413: A single point tool on a lathe are: Chamfering: Cutting an angle on the corner of a cylinder. Parting: The tool is fed radially into the workpiece to cut off the end of a part. Threading : A tool is fed along and across the outside or inside surface of rotating parts to produce external or internal threads . Boring : A single-point tool is fed linearly and parallel to the axis of rotation to create

902-417: A specific form by pouring molten metal into a mold and allowing it to cool, with no mechanical force. Forms of casting include: These forming processes modify metal or workpiece by deforming the object, that is, without removing any material. Forming is done with a system of mechanical forces and, especially for bulk metal forming, with heat. Plastic deformation involves using heat or pressure to make

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984-445: A wide variety of specialized or general-use machine tools capable of creating highly precise, useful products. Many simpler metalworking techniques, such as blacksmithing , are no longer economically competitive on a large scale in developed countries; some of them are still in use in less developed countries, for artisanal or hobby work, or for historical reenactment. The oldest archaeological evidence of copper mining and working

1066-490: A workpiece more conductive to mechanical force. Historically, this and casting were done by blacksmiths, though today the process has been industrialized. In bulk metal forming, the workpiece is generally heated up. These types of forming process involve the application of mechanical force at room temperature. However, some recent developments involve the heating of dies and/or parts. Advancements in automated metalworking technology have made progressive die stamping possible which

1148-430: Is a method that can encompass punching, coining, bending and several other ways below that modify metal at less cost while resulting in less scrap. Cutting is a collection of processes wherein material is brought to a specified geometry by removing excess material using various kinds of tooling to leave a finished part that meets specifications. The net result of cutting is two products, the waste or excess material, and

1230-568: Is a part of the Iron Age . The name comes from the hold that the Roman Empire had begun to exert on the Germanic tribes of Northern Europe . In Scandinavia, there was a great import of goods, such as coins , vessels , bronze images, glass beakers, enameled buckles , weapons, etc. Moreover, the style of metal objects and clay vessels was markedly Roman. Objects such as shears and pawns appear for

1312-407: Is also used, which must be periodically added in order to prevent breaking bits. A milling bit must also be changed as needed in order to prevent damage to the material. Time is the biggest factor for costs. Complex parts can require hours to complete, while very simple parts take only minutes. This in turn varies the production time as well, as each part will require different amounts of time. Safety

1394-412: Is an example of a specialty process that removes excess material by the use of etching chemicals and masking chemicals. There are many technologies available to cut metal, including: Cutting fluid or coolant is used where there is significant friction and heat at the cutting interface between a cutter such as a drill or an end mill and the workpiece. Coolant is generally introduced by a spray across

1476-433: Is believed to have been constructed around 980 during the reign of king Harold Bluetooth and/or Sweyn Forkbeard . Five of the six ring fortresses in historical Denmark have been dated to this era. The exact purpose of the fortress remains uncertain. Some historians have argued that the fortress' primary function was as a barracks or training grounds in connection with Sweyn Forkbeard's armies, which conquered England in

1558-432: Is believed to have been four metres tall. The rampart was constructed of soil and turf, reinforced and clad with oak wood. The rampart formed the basis for a wooden parapet . Smaller streets were located within the four main sections of the fortress. Today, the fortress is approximately 10 meters above sea-level, and 350 meters from the coastline. It is believed the coastline and sea-level at the site had changed over time, as

1640-429: Is combination of grinding and saw tooth cutting using a file . Prior to the development of modern machining equipment it provided a relatively accurate means for the production of small parts, especially those with flat surfaces. The skilled use of a file allowed a machinist to work to fine tolerances and was the hallmark of the craft. Today filing is rarely used as a production technique in industry, though it remains as

1722-574: Is debated why cultural innovation spread geographically during this time: whether the new material culture reflects a possibly warlike movement of Germanic peoples (" demic diffusion ") southwards or whether innovations found at the Pre-Roman Iron Age sites represent a more peaceful trans-cultural diffusion . The current view in the Netherlands is that Iron Age innovations, starting with Hallstatt (800 BC), did not involve intrusions and featured

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1804-456: Is held at the desired height (usually the middle of the workpiece) by the toolpost. The carriage is then moved around the rotating workpiece, and the cutting tool gradually removes material from the workpiece. The tailstock can be slid along the axis of rotation and then locked in place as necessary. It may hold centers to further secure the workpiece, or cutting tools driven into the end of the workpiece. Other operations that can be performed with

1886-440: Is important because it is one indicator of how tightly bound to the ore the metal is likely to be. As can be seen, iron is significantly higher than the other six metals while gold is dramatically lower than the six above it. Gold's low oxidation is one of the main reasons that gold is found in nuggets. These nuggets are relatively pure gold and are workable as they are found. Copper ore, being relatively abundant, and tin ore became

1968-440: Is key with these machines. The bits are traveling at high speeds and removing pieces of usually scalding hot metal. The advantage of having a CNC milling machine is that it protects the machine operator. Turning is a metal cutting process for producing a cylindrical surface with a single point tool. The workpiece is rotated on a spindle and the cutting tool is fed into it radially, axially or both. Producing surfaces perpendicular to

2050-585: Is marked by the arrival of the Corded Ware culture , possibly the first influence in the region of Indo-European expansion . The Nordic Bronze Age proper began roughly one millennium later, around 1500 BC. The end of the Bronze Age is characterized by cultural contact with the Central European La Tène culture ( Celts ), contributing to the development of the Iron Age by the 4th century BC, presumably

2132-423: Is the complex shaping of metal or other materials by removing material to form the final shape. It is generally done on a milling machine , a power-driven machine that in its basic form consists of a milling cutter that rotates about the spindle axis (like a drill ), and a worktable that can move in multiple directions (usually two dimensions [x and y axis] relative to the workpiece). The spindle usually moves in

2214-558: Is the process of shaping and reshaping metals in order to create useful objects, parts, assemblies, and large scale structures. As a term, it covers a wide and diverse range of processes, skills, and tools for producing objects on every scale: from huge ships , buildings, and bridges , down to precise engine parts and delicate jewelry . The historical roots of metalworking predate recorded history; its use spans cultures, civilizations and millennia. It has evolved from shaping soft, native metals like gold with simple hand tools, through

2296-489: Is the process of transferring a design or pattern to a workpiece and is the first step in the handcraft of metalworking. It is performed in many industries or hobbies, although in industry, the repetition eliminates the need to mark out every individual piece. In the metal trades area, marking out consists of transferring the engineer's plan to the workpiece in preparation for the next step, machining or manufacture. Calipers are hand tools designed to precisely measure

2378-671: The 6th millennium BC , the climate of Scandinavia was generally warmer and more humid than today. The bearers of the Nøstvet and Lihult cultures and the Kongemose culture were mesolithic hunter-gatherers. The Kongemose culture was replaced by the Ertebølle culture , adapting to the climatic changes and gradually adopting the Neolithic Revolution , transitioning to the megalithic Funnelbeaker culture . The Pezmog 4 archaeological site along

2460-460: The CNC machine and allow it to complete the tasks required. The milling machine can produce most parts in 3D, but some require the objects to be rotated around the x, y, or z coordinate axis (depending on the need). Tolerances come in a variety of standards, depending on the locale. In countries still using the imperial system, this is usually in the thousandths of an inch (unit known as thou ), depending on

2542-692: The La Tène culture of Central Europe (450 BC to 1st century BC). Although the metal iron came into wider use by metalsmiths in the Mediterranean as far back as c. 1300 BC due to the Late Bronze Age collapse , the Pre-Roman Iron Age of Northern Europe covered the 5th/4th to the 1st centuries BC. The Iron Age in northern Europe is markedly distinct from the Celtic La Tène culture south of it. The old long-range trading networks south–north between

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2624-575: The Limfjord were open waterways when the fortress was constructed and the fjord constituted an important sailing route from the North Sea to the Kattegat . Although the waterway was open, it is speculated that ships had to portage on land past Løgstørgrunde . The portion of the fjord that Aggersborg is located is relatively narrow and was one of the three ancient crossings of the Hærvejen ( army road ) across

2706-704: The Migration Period , starting with the invasions of the Teutons and the Cimbri until their defeat at the Battle of Aquae Sextiae in 102 BC, presaging the more turbulent Roman Iron Age and Migration Period. Fortified settlements from this period include Tönsberg , Erdenburg and Grotenburg in Germany, Borremose in Denmark and Atuatuca in Belgium. The Roman Iron Age (1–400 AD)

2788-683: The Pitted Ware culture Early Indo-European presence likely dates to the early 3rd millennium BC, introducing branches of the Corded Ware culture (such as the Battle Axe Culture ), later be followed by the Nordic Bronze Age . The tripartite division of the Nordic Iron Age into "Pre-Roman Iron Age", "Roman Iron Age" and "Germanic Iron Age" is due to Swedish archaeologist Oscar Montelius . The Pre-Roman Iron Age (5th/4th–1st centuries BC)

2870-664: The Vychegda River ( Komi Republic ) was discovered in 1994. Pottery of early comb ware type appears there already at the beginning of the 6th millennium BC. Pit–Comb Ware culture appeared in northern Europe as early 4200 BC, and continued until c.  2000 BC . Some scholars argue that it is associated with the area of the Uralic languages. During the 4th millennium BC , the Funnelbeaker culture expanded into Sweden up to Uppland . The Nøstvet and Lihult cultures were succeeded by

2952-545: The smelting of ores and hot forging of harder metals like iron , up to and including highly technical modern processes such as machining and welding . It has been used as an industry, a driver of trade, individual hobbies, and in the creation of art; it can be regarded as both a science and a craft. Modern metalworking processes, though diverse and specialized, can be categorized into one of three broad areas known as forming, cutting, or joining processes. Modern metalworking workshops, typically known as machine shops , hold

3034-671: The 3rd century onwards. Through the 5th and 6th centuries, gold and silver become more and more common. This time saw the ransack of the Roman Empire by Germanic tribes, from which many Scandinavians returned with gold and silver. A new Iron Age had begun in Northern Europe, the Germanic Iron Age. The Germanic Iron Age is divided into the Early Germanic Iron Age (EGIA) and the late Germanic Iron Age (LGIA). In Sweden ,

3116-663: The 4th century in Nydam Mose in southern Denmark. The Gudme Hall complex, a ruling elite residence and cult site, was built in Denmark in the 3rd century. At Uppåkra in Sweden, the largest Iron Age settlement in Scandinavia developed from c. 200 AD onwards. A wooden temple was built at Uppåkra in the 3rd century and continued to be used and rebuilt over 600 years, into the early Viking Age. Gamla Uppsala in Sweden developed into an important religious, economic and political centre from

3198-730: The 8th century blends into the Viking Age and the proto-historical period, with legendary or semi-legendary oral tradition recorded a few centuries later in the Gesta Danorum , heroic legend and sagas , and an incipient tradition of primary written documents in the form of runestones . Important royal or elite centres from this period include Gamla Uppsala in Sweden, Lejre and Tissø in Denmark, and Borg (Lofotr) in Norway. [REDACTED] Media related to Archaeology of Northern Europe at Wikimedia Commons Metalworking Metalworking

3280-503: The Bronze Age, but they were a scarce imported material. Similarly, imported bronze continued to be used during the Iron Age in Scandinavia, but it was now much scarcer and mostly used for decoration. Funerary practices continued the Bronze Age tradition of burning corpses and placing the remains in urns , a characteristic of the Urnfield culture. During the previous centuries, influences from

3362-561: The Bronze Age. Some of the most prominent finds from the pre-Roman Iron Age in northern Europe are the Gundestrup cauldron and the Dejbjerg wagons , two four-wheeled wagons of wood with bronze parts. The cultural change that ended the Nordic Bronze Age was influenced by the expansion of Hallstatt culture from the south and accompanied by a changing climate, which caused a dramatic change in

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3444-418: The Central European La Tène culture had spread to Scandinavia from north-western Germany, and there are finds from this period from all the provinces of southern Scandinavia. Archaeologists have found swords, shield bosses, spearheads, scissors, sickles, pincers, knives, needles, buckles, kettles, etc. from this time. Bronze continued to be used for torcs and kettles, the styles of which were continuous from

3526-669: The LGIA (550–800) is usually called the Vendel era ; in Norway and Finland, the Merovinger ( Merovingian ) Age. The Germanic Iron Age begins with the fall of the Roman Empire and the rise of the Germanic kingdoms in Western Europe. It is followed, in Northern Europe and Scandinavia , by the Viking Age . During the decline of the Roman Empire , an abundance of gold flowed into Scandinavia; there are excellent works in gold from this period. Gold

3608-487: The Limfjord. The two other crossings existed to the north of Farstrup , and near Lindholm Høje in Ålborg , respectively. The structure of the ring fortress was completed within one or two years, and only used for a short period of time; between five and twenty years. The ring fortress had an inner diameter of 240 metres. The ditch was located eight metres outside of the rampart, and was approximately 1.3 metres deep. The wall

3690-426: The Mediterranean cultures and Northern Europe had broken down at the end of the Nordic Bronze Age and caused a rapid and deep cultural change in Scandinavia. Bronze, which was an imported alloy, suddenly became very scarce; and iron, which was a local natural resource, slowly became more abundant, as the techniques for extracting, smelting and smithing it were acquired from their Central European Celtic neighbours. Iron

3772-404: The cutting device. This wheel can be made up of various sizes and types of stones, diamonds or inorganic materials. The simplest grinder is a bench grinder or a hand-held angle grinder, for deburring parts or cutting metal with a zip-disc. Grinders have increased in size and complexity with advances in time and technology. From the old days of a manual toolroom grinder sharpening endmills for

3854-414: The distance between two points. Most calipers have two sets of flat, parallel edges used for inner or outer diameter measurements. These calipers can be accurate to within one-thousandth of an inch (25.4 μm). Different types of calipers have different mechanisms for displaying the distance measured. Where larger objects need to be measured with less precision, a tape measure is often used. Casting achieves

3936-458: The driven tool executes the machining operation with a rotating cutting tool. The CNC machines use x, y, and z coordinates in order to control the turning tools and produce the product. Most modern day CNC lathes are able to produce most turned objects in 3D. Nearly all types of metal can be turned, although more time & specialist cutting tools are needed for harder workpieces. There are many threading processes including: cutting threads with

4018-404: The early 1000s. This theory has been disproven by dendrochronological dating of the site. It is more likely that Aggersborg and the other Viking ring fortresses were intended as defensive strongholds along strategic trade points and/or administrative outposts of the budding state. Aggersborg location was of strategic importance, as it was protected but also easily accessible by ship. Both ends of

4100-538: The earth began to evolve, and metalsmiths became more knowledgeable. Metalsmiths became important members of society. Fates and economies of entire civilizations were greatly affected by the availability of metals and metalsmiths. The metalworker depends on the extraction of precious metals to make jewelry , build more efficient electronics , and for industrial and technological applications from construction to shipping containers to rail , and air transport . Without metals, goods and services would cease to move around

4182-468: The edge-durability and stiffness that pure copper lacked. Until the advent of iron, bronze was the most advanced metal for tools and weapons in common use (see Bronze Age for more detail). Outside Southwestern Asia, these same advances and materials were being discovered and used around the world. People in China and Great Britain began using bronze with little time being devoted to copper. Japanese began

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4264-524: The face of the tool and workpiece to decrease friction and temperature at the cutting tool/workpiece interface to prevent excessive tool wear. In practice there are many methods of delivering coolant. The use of an angle grinder in cutting is not preferred as large amounts of harmful sparks and fumes (and particulates ) are generated when compared with using reciprocating saw or band saw . Angle grinders produce sparks when cutting ferrous metals. They also produce shards cutting other materials. Milling

4346-423: The finished part. In woodworking, the waste would be sawdust and excess wood. In cutting metals the waste is chips or swarf and excess metal. Cutting processes fall into one of three major categories: Drilling a hole in a metal part is the most common example of a chip producing process. Using an oxy-fuel cutting torch to separate a plate of steel into smaller pieces is an example of burning. Chemical milling

4428-597: The first time. In the 3rd and 4th centuries, some elements are imported from Germanic tribes that had settled north of the Black Sea , such as the runes . There are also many bog bodies from this time in Denmark , Schleswig and southern Sweden. Together with the bodies, there are weapons, household wares and clothes of wool . The prime burial tradition was cremation, but the third century and thereafter saw an increase in inhumation. Great ships made for rowing have been found from

4510-487: The flora and fauna. In Scandinavia, this period is often called the "Findless Age", due to the lack of archaeological finds. While the archaeological record from Scandinavia is consistent with an initial decline in population, the southern part of the culture, the Jastorf culture , was in expansion southwards. It consequently appears that climate change played an important role in this southward expansion into continental Europe. It

4592-430: The form of a ship; 32.5 metres long and 8.5 metres across. They were divided in a long inner hall, around 19 metres long, with smaller rooms at the end. It is estimated that construction of a single Aggersborg house required 66 large oak trees. The entire structure, housing included, is estimated to have used 5,000 large oaks. Inline citations Germanic Iron Age The archaeology of Northern Europe studies

4674-416: The globe on the scale we know today. Metalworking generally is divided into three categories: forming , cutting , and joining . Most metal cutting is done by high speed steel tools or carbide tools. Each of these categories contains various processes. Prior to most operations, the metal must be marked out and/or measured, depending on the desired finished product. Marking out (also known as layout)

4756-438: The globe. For example, the granulation technique was employed by numerous ancient cultures before the historic record shows people traveled to far regions to share this process. Metalsmiths today still use this and many other ancient techniques. As time progressed, metal objects became more common, and ever more complex. The need to further acquire and work metals grew in importance. Skills related to extracting metal ores from

4838-408: The locus of Common Germanic culture. Northern Europe enters the protohistorical period in the early centuries AD, with the adoption of writing and ethnographic accounts by Roman authors. The following is a refined listing of Northern European archaeological periods, expanded from the basic three-age system with finer subdivisions and extension into the modern historical period. During

4920-949: The necessary materials could be assembled for smelting, heating, and working the metal. Iron was beginning to be smelted and began its emergence as an important metal for tools and weapons. The period that followed became known as the Iron Age . By the historical periods of the Pharaohs in Egypt , the Vedic Kings in India , the Tribes of Israel , and the Maya civilization in North America , among other ancient populations, precious metals began to have value attached to them. In some cases rules for ownership, distribution, and trade were created, enforced, and agreed upon by

5002-436: The next important substances in the story of metalworking. Using heat to smelt copper from ore, a great deal of copper was produced. It was used for both jewelry and simple tools. However, copper by itself was too soft for tools requiring edges and stiffness. At some point tin was added into the molten copper and bronze was developed thereby. Bronze is an alloy of copper and tin. Bronze was an important advance because it had

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5084-593: The past grinders were used for finishing operations only because of limitations of tooling. Modern grinding wheel materials and the use of industrial diamonds or other man-made coatings (cubic boron nitride) on wheel forms have allowed grinders to achieve excellent results in production environments instead of being relegated to the back of the shop. Modern technology has advanced grinding operations to include CNC controls, high material removal rates with high precision, lending itself well to aerospace applications and high volume production runs of precision components. Filing

5166-435: The piece. The spindle rotates at high speed, providing the energy to cut the material. While historically lathes were powered by belts from a line shaft , modern examples uses electric motors. The workpiece extends out of the spindle along the axis of rotation above the flat bed. The carriage is a platform that can be moved, precisely and independently parallel and perpendicular to the axis of rotation. A hardened cutting tool

5248-621: The prehistory of Scandinavia and the adjacent North European Plain , roughly corresponding to the territories of modern Sweden , Norway , Denmark , northern Germany , Poland , the Netherlands and Belgium . The region entered the Mesolithic around the 7th millennium BC. The transition to the Neolithic is characterized by the Funnelbeaker culture in the 4th millennium BC. The Chalcolithic

5330-761: The process of liberating metals from rock by heat became known, and rocks rich in copper, tin , and lead came into demand. These ores were mined wherever they were recognized. Remnants of such ancient mines have been found all over Southwestern Asia . Metalworking was being carried out by the South Asian inhabitants of Mehrgarh between 7000 and 3300 BCE. The end of the beginning of metalworking occurs sometime around 6000 BCE when copper smelting became common in Southwestern Asia. Ancient civilisations knew of seven metals. Here they are arranged in order of their oxidation potential (in volts ): The oxidation potential

5412-432: The respective peoples. By the above periods metalworkers were very skilled at creating objects of adornment, religious artifacts, and trade instruments of precious metals (non-ferrous), as well as weaponry usually of ferrous metals and/or alloys . These skills were well executed. The techniques were practiced by artisans, blacksmiths , atharvavedic practitioners, alchemists , and other categories of metalworkers around

5494-474: The ring fortress at the site. These artefacts include a variety of common household objects: pottery, iron tools and weapons, jewellery, and coins. Very few traces of specialised craft were uncovered, e.g. evidence of metalworking or refuse from bone-working. These artefacts also included a number of objects of import, primarily from Norway, but also western Europe and the British Isles . Based on these objects,

5576-603: The ring fortress could hold a 5,000-man garrison , located in 48 longhouses . Twelve longhouses were located in each quadrant, all located on a north–south or west–east axis. No remains of the actual houses exist, but proof of the location of the walls has been found. The individual houses are believed to have been similar to the form seen on the Camnin chest , a house-shaped reliquary , as well as on house-shaped tombstones in England . The houses had curved roofs and curved sides, similar to

5658-594: The same permeating Roman influence seen in most other artifacts from the early centuries AD, indicating that parts of northern Europe had not yet come into contact with the Romans at the beginning of the Iron Age. Out of the Late Bronze Age Urnfield culture of the 12th century BC developed the Early Iron Age Hallstatt culture of Central Europe from the 8th to 6th centuries BC, which was followed by

5740-485: The site's total area and recorded some 19,500 individual features. The large number of archaeological finds discovered on the site include many imported luxury items. Examples include beads of mountain crystal and pieces of glass jars. A damaged golden ring has been discovered on the site as well; a replica is displayed in the Aggersborg museum. Excavations have also uncovered artefacts from the Iron Age village which predated

5822-529: The specific machine. In many other European countries, standards following the ISO are used instead. In order to keep both the bit and material cool, a high temperature coolant is used. In most cases the coolant is sprayed from a hose directly onto the bit and material. This coolant can either be machine or user controlled, depending on the machine. Materials that can be milled range from aluminum to stainless steel and almost everything in between. Each material requires

5904-563: The strait was once much wider, reaching closer to the fortress itself. The modern Aggersborg is a reconstruction created in the 1990s. It is lower than the original fortress. Several archaeological excavations have been carried out at the site since the 20th century. The National Museum of Denmark conducted significant excavations of the site between 1945 and 1954. In 1970 and again in 1990, additional trenches were studied. Together, these excavations recovered more than 30,000 artefacts and many animal remains. They covered approximately 13,000 m of

5986-503: The use of bronze and iron almost simultaneously. In the Americas it was different. Although the peoples of the Americas knew of metals, it was not until the European colonisation that metalworking for tools and weapons became common. Jewelry and art were the principal uses of metals in the Americas prior to European influence. About 2700 BCE, production of bronze was common in locales where

6068-508: The village was likely settled in the late 8th century and demolished during the 10th century. After the fortress which replaced it was abandoned, the village was not resettled, though artefacts from the period which immediately followed have been found in areas near the site. The site's ring fortress structure is typified by its earthen rampart and its carefully aligned circular design, comprising wooded structures and buildings which are arranged into courtyards. Archaeologists have estimated that

6150-415: The workpiece axis is called facing. Producing surfaces using both radial and axial feeds is called profiling. A lathe is a machine tool which spins a block or cylinder of material so that when abrasive , cutting, or deformation tools are applied to the workpiece, it can be shaped to produce an object which has rotational symmetry about an axis of rotation . Examples of objects that can be produced on

6232-533: The world come from the Bulgarian Varna Necropolis and date from 4450 BCE. Not all metal required fire to obtain it or work it. Isaac Asimov speculated that gold was the "first metal". His reasoning being, that, by its chemistry , it is found in nature as nuggets of pure gold. In other words, gold, as rare as it is, is sometimes found in nature as a native metal . Some metals can also be found in meteors . Almost all other metals are found in ores ,

6314-495: The z axis. It is possible to raise the table (where the workpiece rests). Milling machines may be operated manually or under computer numerical control (CNC), and can perform a vast number of complex operations, such as slot cutting, planing , drilling and threading , rabbeting , routing , etc. Two common types of mills are the horizontal mill and vertical mill. The pieces produced are usually complex 3D objects that are converted into x, y, and z coordinates that are then fed into

6396-458: Was extracted from bog iron in peat bogs, and the first iron objects to be fabricated were needles and edged tools such as swords and sickles. The rise of iron use in Scandinavia was slow: bog ore was only abundant in southwestern Jutland and it was not until 200–100 BC that iron-working techniques were generally mastered and a productive smithing industry had evolved in the larger settlements. Iron products were also known in Scandinavia during

6478-482: Was inscribed on the UNESCO World Heritage List . Dating the structure has proven difficult, because it was the site of an Iron Age village before the construction of the ring fortress. Archaeological finds suggest that this village was settled during the late 8th century. It was destroyed during the 10th century, and the grounds were cleared for the construction of the fortress. The ring fortress itself

6560-504: Was the discovery of a copper pendant in northern Iraq from 8,700 BCE. The earliest substantiated and dated evidence of metalworking in the Americas was the processing of copper in Wisconsin , near Lake Michigan . Copper was hammered until it became brittle, then heated so it could be worked further. In America, this technology is dated to about 4000–5000 BCE. The oldest gold artifacts in

6642-613: Was the earliest part of the Iron Age in Scandinavia and the North European Plain . Succeeding the Nordic Bronze Age , the Iron Age developed in contact with the Hallstatt culture in Central Europe. Archaeologists first decided to divide the Iron Age of Northern Europe into distinct pre-Roman and Roman Iron Ages after Emil Vedel unearthed a number of Iron Age artifacts in 1866 on the island of Bornholm . They did not exhibit

6724-587: Was used to make scabbard mountings and bracteates . After the Western Roman Empire fell, gold became scarce and Scandinavians began to make objects of gilded bronze, with decorative figures of interlacing animals . During the EGIA, decorations tended to be representational; the animal figures were drawn in more basic forms. In the LGIA, artistic styles became more abstract, symbolic, and intricate, including figures with interlaced shapes and limbs. The LGIA in

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