| 3. Early Eighteenth-Century Steel Production
In little over a century, Sheffield made the
transition from a small market town specialising in cutlery wares
and edge tools into the world's greatest steel manufacturing city.
The reasons for this dramatic transformation are complex, yet
had it not been for the invention of a Yorkshire clock-maker,
the city's development may have been very different.
Benjamin Huntsman's invention of crucible cast steel paved the
way for all modern steel casting and alloying processes, without
which the developments of the last century would have been inconceivable.
Friedrich Engels even attributed the development of England's
industrial might to Huntsman's discovery, by virtue of the high
quality tools and machinery it made possible.
Although cutlery and steel-making had been practised in Sheffield
long before the introduction of Huntsman's process, it was the
latter that provided the catalyst for the city's developing steel
industry, without which the later heavy industries of the Don
Valley -- the source of Sheffield's great fortunes -- would almost
certainly not have developed there.
Huntsman's crucible process is a deceptively simple idea. Pieces
of common cementation steel are placed in a clay crucible or "pot",
melted down in a sufficiently hot air furnace, and the molten
metal finally poured into a cast-iron ingot mould. However, the
technological barriers to its development were considerable. Never
before had a practically sized furnace reached such temperatures,
nor were the clay crucibles of the day strong enough to withstand
the intense heat needed to melt steel. These were the challenges
to which Huntsman devoted much of his life.
The process had an extremely long lifespan compared to most inventions,
remaining in commercial use for over two hundred years. Until
the 1860s, all steel castings from the smallest ingots to the
largest castings of many tons weight were still made of metal
poured from individual crucibles, and for applications dependent
on special alloy steels its use continued well into the twentieth
century. Sheffield almost monopolised the world market for cast
steel, and over the two centuries of its production, the bulk
of the world's crucible steel came out of Sheffield.
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