Wootz “Damascus Steel”: History, Metallurgy, Production
This is going to be a rather long, and in depth video on wootz steel, it’s history, metallurgy, and production. For the most part, it is based upon excellent academic work by Ann Feuerbach and metallurgical experimentation by John Verhoeven.
Historically (prior to the 18th century), “Damascus Steel” also referred to wootz, or crucible steel, which was produced all over South East and Central Asia and the middle east. In order to differentiate between the two forms of “Damascus”, I will be using the nomenclature of pattern welded steel, and wootz steel.
Also known as pulad, fulad or bulat, wootz is an ancient crucible steel, which was produced from as early as the first century, CE. It is typified by being high in carbon content, usually between 1 and 2 percent and a low slag content.
Metallurgical identification of wootz steel is problematic, as no single criteria can be used to differentiate between crucible steel, and decarburised wrought iron. In order to confidently say whether a sword is crucible steel or not, the blade must be polished and then etched in nital, and examined via low magnification microscopy. The presense of spheroidised cementite is considered evidence of a crucible produced steel.
Wootz can occur in two different forms according to Ann Feuerbach, soft wootz with less than 0.8% carbon, and hard wootz with greater than 0.8%. The vast majority of pattern presenting wootz and historical wootz is hard wootz, whereas the majority of crucible steel that produces no pattern is soft wootz.
The names Pulad and Fulad derive their meaning from the words for Purified, and fittingly Wootz also typically contains lower levels of slag than other steels, such as bloomery iron or decarburised wrought iron, however if the wootz was made using one of these as a source of iron, this can introduce slag into the final product.
For the most part, the clay crucible would be filled with a charge. This crucible charge would contain iron, often a mix of “soft and hard iron”, referred to by Al Kindi as male and female iron, as well as some form of plant matter such as rice husks, pomegranate peels, wood chips, leaves or vines. These served two purposes: Firstly, to provide carbon to the steel, without which it would not melt and would not produce useable steel, and secondly to produce gasses as they pyrolise, protecting the steel from the atmosphere of the furnace. Some processed such as the Deccani process utilised in Hyderabad used glass as a protective flux.
The crucible was heated for anywhere between 6 hours (as in the south Indian process) to two days, as in the Deccani process, or as much as 6 days in the Isfahan process. The resulting wootz button or egg was then polished in order to check the quality of the wootz.
In the Isfahan process, the wootz ingots were taken from their crucibles after firing, and placed in a heated room or compartment for two days, to temper them and relieve stresses prior to forging.
Isfahan wootz is particularly well known, as is Khorasani steel. The most famous of persian swordmakers hailed from Isfahan, Assad Allah, during the reign of Shah Abbas. There is an interesting legend as to how he rose to such prominence.
According to this legend, Shah Abbas held a competition with the intention of finding a new shamshiraz, or swordmaker for his court. In order to root out the best of the best, he offered a prize for a swordsmith who could cut an iron helmet given to him by an ottoman sultan, without damaging their sword. All failed, but one. Assad Allah, whose name literally translates to Lion of God, approached the helmet, swung, and cleaved it in two, without rolling an edge.
The secret to producing wootz steel was lost for a long time, as the ore sourced dried up around 1750, and wootz production ground to a halt. Crucible steel was still being made, but it lacked the distinct patterns in the steel, which had served as a guarantee of quality. It was only recently through the combined efforts of John Verhoeven and the late Al Pendray that it was revealed that trace amounts of carbide forming elements are responsible for the formation of wootz patterns. In particular, the pair discovered that vanadium was a vital alloying element in pattern formation.
Recently, Verhoeven has revisited the topic with a 2018 paper titled Damascus Steel Revisited, in which experimentation solidified his claim that internal banded microstructures resulted from microsegregation of Vanadium between dendritic and interdendritic regions of the ingot during solidification. Vanadium therefore acts as a nucleation point for cementite spheroid formation, leading to linearly aligned bands of cementite after forging.
To answer this question I have selected excerpts from “Swords: How they are made and something about curious ones” by Frank Lamburn, Pearson’s Magazine, Vol. 2, July to December, 1896, which details how Wilkinson made swords.
The early stages of the process are essentially similar in a
broad sense to those passed through by most other pieces of cutlery. The steel,
of Sheffield make, is drawn into strips, equal in length to two blades, cut in
half, heated in a furnace, and hammered out until it resembles roughly a sword
An iron tang, designed eventually to receive the hilt, is
welded on to the steel and the blade is tempered. In tempering, each blade is
made hot singly, plunged into a bath of tepid water containing certain chemical
ingredients, drawn out–at this stage it is glass hard, being so brittle that
if dropped it would break in a dozen pieces–and slowly heated over the fire
until sufficiently tempered.
This operation can
only be performed at its best when the day is bright. During the winter month,s
on account of the poor light, the average time available for hardening is only
two days a week.
Beyond this point the blade may not again be worked in the
forge; further heating would decarbonise it. In converting blades from one
shape to another they are reheated, with the result that too great a quantity
of carbon is extracted and the steel becomes soft and of inferior quality.
After the blade has been cut and trimmed to the regulation
size, it passes to a man at one of the enormous Newcastle and Leeds stones
constituting the grinding department. During this operation five or six ounces
of metal are removed from the blade before it is finally brought down to
correspond with the rough gauges of thickness and width. Although the stone is
particularly hard, the steel causes it to fly off in thin, wet streams, and
wears it away to a degree that results in a stone seven feet in diameter being
reduced to two feet in diameter in about six months.
When the blade comes from this room it is a dull bright, and
requires to be polished, but it is never sharpened before it leaves the factory
unless in compliance with a special order. Before going on active service, the
bayonets and swords of all the soldiers and officers ordered away are returned
to Enfield to have a cutting edge put on them.
Before the hilt and guard are fixed to Government blades,
they undergo a number of severe tests on the premises at the hands of a
Government inspector. So far as the blade is concerned, the polished blade is
laid in a trough–a length of solid, three inch thick steel, with the exact
shape of the blade cut in the surface–and it has to fit this at every point
along its edge.
Next, the blade is bent round a semi-circular sheet of steel,
covered with a wire netting to protect the operator in the event of breakage,
after which it is placed in a machine that causes it to strike with its edge a
block of oak with a force of 160 pounds, and on its flat sides a sheet of iron
with a force of 80 pounds. In another machine it has to bear a vertical
pressure of 180 pounds without bending. When the handle is fixed, the weapon is
struck by hand on a solid block of oak, and the operator can tell by the ring
whether the blade is sound and if the grip is securely attached.
In testing cavalry swords, the blade is struck under the
same conditions as the bayonet, is placed in a machine and pressed on the top
while in a vertical position, until it is shortened four inches, and must bear
a 28lb vertical pressure without bending. As the result of a scientific
investigation instituted by the Government, it was recently discovered that in
pressing on a blade so that it bent first on one side, then on the other–a
common practice among infantry officers–the fibre of the metal was injuriously
strained; when, therefore, the vertical pressure test is applied and the blade
sprung, a small cross is stamped on the convex side to denote that the sword
may be sprung only on that side.
The sword-grip is automatically carved from a block of hard
Italian walnut. A block of wood is placed in the machine and left for three
minutes, when it is taken out in its completed form. This grip is covered with
the skin of a Japanese fish–the only suitable material–and bound with silver
wire after which the guard, stamped or cut, according to the quality, from a
flat sheet of metal is attached.
Although the average weight of the British officer’s sword
is only a pound and three-quarters (this is heavier than the French and United
States sword, but lighter than those of other nations), it is quite possible
for him to avert a blow delivered from a heavy tulwar, provided he catches it on
that portion of the blade nearest the hilt, and is sufficiently skillful in the
art of fencing. It is essential, of course, in a case of this kind that the
steel should be of the finest possible temper, and for this reason British
blades are sent out to the Indian Army, where they are fitted by regimental
armourers with hilts of regulation pattern.
The fate of old swords is very ordinary. Those belonging to
officers are, as a rule, preserved in the family, being handed down to father
and son; and in order to assist in carrying out this custom, the Wilkinson
Company keep a record which enables them to return the sword of any officer
killed on active service to his relatives at home. The swords of privates, when
returned to the Government Stores, are retested, and, if serviceable, are again
issued, or if unserviceable, are cut in half, the proof marks effaced, and sold
as scrap. They are then sent to Belgium, where they are welded together again
and returned to this country and offered for sale.
Below: Making swords at the Wilkinson Sword factory.
Still making them as they were made in the 19th century!
Additionally, here is an account of how swords were made at Charles Reeves’ Toledo Works factory in Birmingham, from England’s Workshops by Dr. G.L.M. Strauss, Charles William Quin, John Cargill Brough, Thomas Archer, William Bernhard Tegetmeier, and William Jeffery Prowse, London, 1864.
The steel from which the swords are made is supplied (by Mr.
John Sanderson of Sheffield) in long pieces somewhat tapering at each end, and
having a square portion in the middle, which being cut through, leaves material
for two blades, the bisection of the square leaving a shoulder at one end to
receive the iron “tang” by which the blade is afterwards fixed into the handle.
The manufacture of these blades is almost entirely effected by the forgers, who
hammer them into the required shape upon the anvil, a mould running down the
centre of which secures the hollow which in swords extends for about two thirds
of the length from hilt to point. In a little street of smithies the musical
clink is being sounded by a score of stalwart arms, either forging the rough
steel into form or hammering the formed blade into perfect shape and symmetry,
an operation which requires it to be kept at a certain heat lest the embryo
blade should be injured in the process. Once perfected as to proportion, the
hardening commences, and the blade is thrust backward and forward into the
furnace until it has acquired a proper and uniform heat, at which point it is
removed and instantly plunged into cold water. This process, which has
obviously suggested the Turkish bath, renders it hard indeed, but at the same
time so extremely brittle that we whisperingly suggest the propriety of
contracting to supply our enemies with weapons and neglecting to carry them
beyond that particular stage of preparation when they may be snapped with the
fingers. Carefully supported, however, the blade is again subjected to the
fiery ordeal until it attains a slaty-blue colour and a beautiful and elastic
temper, which has been partially secured by the previous hammering. By the
process of forging it has become about six inches longer than the pristine
steel shape, and by the tempering it has attained a springy strength which
enables it to be bent in a curve sufficient to bring the hand five inches
nearer the point.
There is yet another operation before the blades are taken
to the finishing-shop, one of the most important, too, since it is no other
than grinding, a process which secures an exact and uniform thickness, and
increases their elasticity.
We are standing at
the open end of a long, vast, and gloomy shed-like building, supported by iron
pillars. On each side through the entire length a series of enormous
grindstones spin round amidst sand and water and the mud from both. Seated
astride the bodies of wooden horses, whose heads seem to have been transformed
into these wheels, the grinders seize upon the blades, and each fearless rider
rising in his stirrups–or what looks much the same standing tiptoe till he no
longer touches his saddle–throws himself forward and presses the sword,
matchet, or bayonet on the wheel, at the same time guiding it deftly with his
left hand till its whole surface has been smoothly ground.
Along the whole line of whirling stones fly the lurid red
sparks; and as the grinders, with squared elbows, seem to curb the struggling
and impetuous wheels, we think of the wild dreams of Callot or Dore, and fancy
a double rank of riders bestriding horses strangely foaled by some hideous
After polishing, which is completed by wooden wheels bearing
a coating of leather covered with emery, the swords and matchets go to receive
handles, and the bayonets locking-rings. The handles of swords are made of
walnut-wood covered with the skin of the dogfish, while the hilt and guard are
formed from a plain flat sheet of steel, in shape not unlike one side of a pair
The illustrations of blade cross sections from John Latham’s lecture, “The Shape of Sword Blades”, which he delivered on Monday, May 5th, 1862 and published in Journal of the Royal United Service Institution, Volume 6.