Metalworking and the Smith

[Dept of PMM Artists & things]

Iron is found in iron ore (rock) and the first stage of ironmaking is to extract the metal from the ore. This is best done at the place where the iron ore is dug out of the ground, otherwise a lot of waste material has to be carried about. It is thought that iron was brought to Jorvik (York) as ingots (bars of iron) already extracted from the ore. Some probably came from the Lake District, the North York Moors; some came from Scandinavia where richer ores are to be found. Once in Jorvik, the ingots could be heated up again by smiths who could then forge (hammer) them into the shapes they wanted. Or it could be melted right down again and cast (poured) into ready-shaped stone or clay moulds. After casting, some more work could be done on the object to finish it - filing, re-heating and forging, polishing and perhaps putting some sort of decoration on. Steel is iron which has been combined with fairly pure carbon and it is much better than iron for keeping a sharp edge. But good steel was difficult to make in the Viking Age and probably only small quantities could be made at any one time. Steel had to be used sparingly, so it was used for the cutting edges and points of iron tools and weapons. An expensive and very strong knife, sword or axe could be made by forging alternate layers of iron and steel together. To decorate iron items, strips of steel, copper or precious metals could be inlaid in them during forging. Some metalworking techniques and terms forging Heating metal in a furnace or hearth until it is red- or white-hot, then hammering, bending and punching it into shape. casting Heating metal until it is liquid, then pouring it into ready-shaped moulds (made of stone, clay or sand) and allowing it to cool and set. rivetting Fastening two or more pieces of material together. Matching holes are made in the pieces, then a rivet (peg) is pushed through the holes and hammered over tightly at each side to form 'mushroom' heads which clamp the pieces together. If the pieces being fastened together are metal, then the rivet is heated up and as it cools and contracts it tightens. Soft metal rivets can be used for 'cold' rivetting where heat would be undesirable (such as rivetting bone or wooden handle strips to a knife blade). welding A process for bonding metal pieces by heating them to red or white heat then hammering them together so they fuse into one. Pattern-welding was done by welding strips of a different metal to the surface of, for example, a blade. furnace An enclosed oven-like structure, made of stone or clay (or clay-lined stone) in which iron can be extracted from its ore. The ore would be placed in the furnace on a bed of wood or charcoal and the chamber brought to a high temperature using bellows, blowing into the furnace through a nozzle (tuyère). A simple, primitive furnace may have no bellows but rely on an opening facing the wind but it would be impossible to reach really high temperatures this way. A small opening in the top of the furnace allows smoke to escape. The process is known as smelting and the smelted metal runs out of the ore and either gathers at the base of the furnace or is run off into moulds to set as ingots. hearth An open furnace, used by smiths to re-heat ingots and metal items ready for shaping. Hearth temperature would be raised by the use of bellows. The normal fuel would be charcoal. bellows A device for directing a stream of air at fuel in a furnace or hearth, so that it has a rich supply of oxygen. This makes the burning fierce for the high temperatures needed for smelting ore or working metal. A simple bellows might be a hide or skin bag with a fine outlet nozzle of metal, wood or bone. Squeezing and pulling the bag would produce the stream of air which is directed at the fuel. It would normally be the job of an ironmaker's or blacksmith's assistant, or an apprentice, to do the pumping. anvil A hard block on which the smith forges, bends, stretches, welds and punches metal. A strong flat stone would serve the purpose - or even a tree stump with a flat stone or flat metal plate on top. The best anvil, though, is one made entirely of cast iron, with a smooth, flat surface on top, a tapering 'beak' at one end, and some holes for punching through. A large all-iron anvil would be difficult to make in the Viking Age because of the great mass of cast iron needed at one time. A small anvil was found by archaeologists at the Jorvik site. soldering Bonding light or soft metal together with molten tin, lead, silver or gold, or alloys of these metals. brazing Bonding light or soft metal together with molten brass or copper alloys. blacksmith A craftsman who works mainly with iron and steel. Often called simply a 'smith' and in the Viking Age a smith would often be an all-round metalworker, working with copper, bronze, lead, tin, and precious metals, as well as iron and steel. In later times, each type of metal had its own specialist craftsmen, such as silversmiths, tinsmiths, and so on. In Jorvik, smiths may have been involved in the minting of coins and making and repairing jewellery. farrier One who makes and fits shoes to horses. Farriery was normally part of a blacksmith's work. alloy A mixture of two or more metals. Bronze, for example, is an alloy of copper and tin. plating Giving one metal a thin coating of another metal to improve its appearance, for decoration, or to protect the core metal against corrosion. Plating processes in the Viking Age would probably have been crude and may simply have involved briefly dipping the core object in the molten plating metal, or melting the plating metal over the object. Tin, tin-lead alloy and copper alloy plated items have been found at Jorvik. quenching Plunging hot metal into water after it has been forged to shape. It is important to judge exactly the right time to do this. If it is done too soon the metal may become brittle and shatter easily; but leave it too long to quench and the metal may be too soft to sharpen into an edge. Sometimes, it is necessary to re-heat metal to the correct temperature before quenching it. The smith's skill with quenching iron/steel is in watching the colour change as it cools from near-white, to bright red, through to cherry red, then very dark red. Quenching takes place when the colour is judged correct for the purpose of the item, such as cutting, chiselling, striking, or bending. Steel can be specially quenched (tempered) by plunging it into oil instead of water; this makes it slightly springy and able to bend in a way that would shatter iron or untempered steel. Magic ! The skills and processes of working metal (especially iron) were a mystery to most people in ancient and Viking times and were thought by superstitious people to be magical. 'Magical' iron and skilled smiths feature in the myths and legends of the Anglo-Saxon, Scandinavian and other Germanic peoples. A well-known mythical figure is Weyland the Smith. The iron horseshoe - one of the typical products of the smith - is still regarded as a 'magical' symbol today and is hung on walls and doors to bring good luck (but only if the curved part is at the bottom, otherwise the luck 'falls out' !). Smiths probably added to the sense of mystery by carefully guarding the secrets of their craft, revealing them only to their chosen apprentices, who would often be their own sons or other members of the family. This made the smith an important figure in the community and every village probably had its own smith, or family of smiths, which is why the family name Smith is the most common one in Great Britain, with equivalents in many other countries. This shows how important was the smith and his work in many parts of the world. Rulers and important noblemen would often have their own personal smith. A Viking Age trading town like Jorvik (York) would have had work for several smiths at any one time.

- 15. april 2000 -