Anvil
(selectively transcribed from Wikipedia, still needs work.)
An anvil is a metalworking tool consisting of a large block of metal (usually forged or cast steel), with a flattened top surface, upon which another object is struck (or "worked").
Anvils are massive because the higher their inertia, the more efficiently they cause the energy of striking tools to be transferred to the work piece. In most cases the anvil is used as a forging tool.
The great majority of anvils are made of cast steel that has been heat treated. Inexpensive anvils have been made of cast iron and low-quality steel, but are considered unsuitable for serious use, as they deform and lack rebound when struck.
Structure
The primary work surface of the anvil is known as the face. It is generally made of hardened steel and should be flat and smooth with rounded edges for most work. Any marks on the face will be transferred to the work. Also, sharp edges tend to cut into the metal being worked and may cause cracks to form in the workpiece.
The horn of the anvil is a conical projection used to form various round shapes and is generally unhardened steel or iron. The horn is used mostly in bending operations.
The step is the area of the anvil between the "horn" and the "face". It is soft and is used for cutting; its purpose is to prevent damaging the steel face of the anvil by conducting such operations there and so as not to damage the cutting edge of the chisel, though many smiths shun this practice as it will damage the anvil over time.
The hardy hole is a square hole into which specialized forming and cutting tools, called hardy tools, are placed. It is also used in punching and bending operations. These are not to be confused with swage blocks, although their purpose is similar.
The pritchel hole is a small round hole that is present on most modern anvils. Some anvils have more than one. It is used mostly for punching. At times, smiths will fit a second tool to this hole to allow the smith more flexibility when using more than one anvil tool.
Suitable Materials
The face is hardened and tempered to resist the blows of the smith's hammer, so the anvil face does not deform under repeated use. A hard anvil face also reduces the amount of force lost in each hammer blow. Hammers, tools, and work pieces of hardened steel should never directly strike the anvil face with full force, as they may damage it; this can result in chipping or deforming of the anvil face.
A common blacksmith's anvil is made of either forged or cast steel, forged wrought iron with a hard steel face or cast iron with a hard steel face. Cast iron anvils are not used for forging as they are incapable of standing up to the impact and will crack and dent. Also, cast iron anvils without a hard steel face do not have the rebound that a harder anvil would and will tire out the smith.
Cheap anvils made from inferior steel or cast iron are considered unsuitable for serious use. Amateur smiths have used lengths of railroad rail, forklift tines, or even simple blocks of steel as makeshift anvils.
Placement
The anvil is placed as near to the forge as is convenient, generally no more than one step from the forge to prevent heat loss in the work piece. An anvil needs to be placed upon a sturdy base made from an impact and fire resistant material. Common methods of attaching an anvil are spikes, chains, steel or iron straps, clips, bolts where there are holes provided, and cables.