First, one should recognize there is no "standard" anvil.
During the early part of the twentieth century, shortly before the automobile and other technical advances put the American Blacksmith out of business, anvils were made in great quantity and under great competition. Most anvils were made in the London pattern or it's modification the American pattern (narrower waist, mass moved into horn and heal). Other than this brief period anvils were made in a great variety.
Today there are still a number of manufactures making anvils but in small quantities and there are still organizations and individuals that make anvils to suit themselves.
Any book on blacksmithing will give the shape and basic nomenclature.
Start with Bealer's classic The Art of Blacksmithing, p.65 Medieval Anvils, p.66 The London Anvil and nomenclature, p.68 A Liêges anvil. Then try Eric Sloane's A Museum of Early American Tools, pp.90-93 Early, Colonial, Stake, Nailers.
And for a classic of custom design see Otto Schmirler's
Werk und Werkzeug des Kunstschmieds,
the most beautifully illustrated book about Blacksmithing that I've ever seen.
Old industrial catalogs will often include photos and specs of the anvils they carried. Industrial Supply Corp., Richmond, VA, 1955 catalog, page 172 lists Fisher "Eagle" Anvils from 50 to 700 pounds,
"The face is made from one piece of high grade tool steel, accurately ground and tempered. Will not settle, break or become loose. Horn is a solid piece of forged steel. Body is of gun iron".
This catalog also included a variety Blacksmith's hand tools and forges.
Reprints of catalogs such as old Sears and Roebucks are also a good source of anvil data. In 1984 the Mid-West Tool Collectors reprinted the 1915 Sears, Roebuck and Co., Tools Machinery Blacksmith's Supplies catalogue. In 1985 the same catalog was reprinted a second time in cooperation with A.B.A.N.A. It includes "Acme" (probably Hay-Buden) steel faced wrought iron anvils, "Steel Face Cast Anvils" and "Chilled Face Cast Iron Anvils." Weights range from 220 pounds to 20 pounds.
Specialty anvils such as the Farriers anvil sometimes have a bulge to one side of the horn for forging caulks. V-grooves ground in the face are also offered. Today's American made Farriers Anvil has a very narrow waist (approx equal to the face width) and exaggerated horn and heal. They are not suitable for general work. Formerly, Hay-Budden produced a Farriers anvil that was their standard anvil with one corner of the table removed and two pritchel holes (one extra). Currently European anvils are big on an added block on one side of the anvil extending to the base called an upsetting block. Europeans are also keen on double horned anvils (one conical, one pyramidal). THEN, if we wish to avoid being Eurocentric in our views, the classic Japanese anvil was a rectangular block set into the ground the smith also sitting on the ground. This Eastern way of working was practiced in Ancient Greece and is still practiced in India and Southeast Asia.
Other specialty anvils include the ancient Nailers anvil, Sawyers anvils, Armorer's anvils, Jewelers anvils and various stake anvils.
CUSTOM ANVILS: Surprisingly custom made anvils are more common than you would think. Otto Schmirler's personal anvils mentioned above were made of cast steel from his own patterns in several sizes. At Colonial Williamsburg they wanted anvils with an old look but did not want to be wearing out real antiques. They had anvils cast (probably in ductile iron) and hard faced using special welding rod (Eutectic(tm) most likely). I knew a blacksmith that used an anvil built by lamination of plates arc welded together. There are also railroad track anvils, I-beam anvils (not recomended) and I've had numerous requests for information on ordering square heavy plate student anvils (10x10x4" - 113#). Then there's my 500lb. cut from 4145 plate custom anvil design that I will probably never make. . .
MATERIALS: The earliest anvils were stone and used for working stone. Bronze age anvils were mostly stone but it would seem that bronze would work, developing a very hard surface from work hardening. Granite would have made the best stone anvil.
It has been postulated by historians that the earliest anvil was meteoric iron. However, rare meteoric iron would have been much too valuable to use when a common piece of granite would do. The first iron anvils would come with the iron age. For centuries anvils were made of wrought iron with a thin layer of steel welded to the face. As steel became more common these plates became thicker but were often a cause of failure. Not until the 1800's did crucible steel become common enough to use a plate thick enough to be reliable.
Today most good quality anvils are made of cast steel the type dependent on the manufacturer. There are also a large number of cast iron "shop anvils" sold. Cast iron anvils are worthless for forging as they are dead (no rebound) and very brittle.
Modern anvils have been made by a number of methods.
Wrought iron bodies with heavy face plates welded on.
Cast iron or ductile iron bodies cast onto a steel face plate.
Ductile iron castings with the face heat treated.
Solid steel castings (hardened and occasionally tempered).
All these methods make fine anvils. They all have their good and
HARDNESS: Ideally the face of an anvil should be as hard as it can be made.
Problems arise at the corners where hard means brittle and corners shatter.
Selective tempering helps but sometimes leaves corners too soft.
Studying used anvils it is obvious that the faces are generally as hard as can be made with a mild tempering.
Typically I have found that small anvils (less than 150 pounds) have very hard faces and corners.
As anvils get progressively larger they tend to have progressively softer corners.
I believe this is due to an inability to get a good quench on bigger anvils and possibly due to manufacturers tempering them to prevent breakage.
My 11th edition of Machinery's Handbook (1942) has a paragraph on anvils but nothing specific about hardness.
One must also consider that the majority of anvils in existence were manufactured before hardness testing was common or any type of standards existed.
I would guess that high quality anvils were faced with 80 point carbon steel and hardened and tempered to 60-65 Rockwell C.
There also may have been additional selective tempering around the edges to 45-50 Rc.