But in technical terms chains
are classified in seven broad groups: cable; chain types derived from cable;
curb; other wire chains; pressed chains; chains made from turned parts; and
fancy chains.
Most chain is now made automatically
by machine but the tradition of handmade chain continues where it is impractical
by machine or the quantities are small, as with such picturesque styles as snail’s
shell and fishbone chain.
The first description of
chain-making came in 1122 from Theophilus,
who recommended using a board of oak or beech wood drilled with holes made by
a red hot iron spike through which the chain
could be drawn to the desired diameter and shape and then wound on a spindle.
Chain is made from wires or tapes of carat gold alloy,
which may be either solid or hollow to reduce weight. For hollow chain, a carat
gold shell is sometimes formed around a core of aluminium or soft iron wire
to provide the necessary strength for manufacture, after which the internal
wire is dissolved out chemically. Machine-made
chain may also be made from wires that
have a core of carat gold solder to aid the
closing of the links by soldering. The links of chain
from solid wires are frequently soldered with copper/silver powders, usually
in a controlled atmosphere conveyor furnace. The joining of links by laser,
gas plasma microtorch or electric discharge welding on-line during
chain-making is also finding increasing application.
Chain
Gold
chain is both one of the oldest and one of the most popular forms of jewellery.
It is also made in a multiplicity of styles; well over two hundred varieties are
available. The names of these may reflect their appearance (foxtail, snake, barleycorn),
their geographical origin (Byzantine, Venetian, Madeira, Russian), their historical
origin (curb chain, named after the German panzerhemd
or coat of mail), historical persons (Garibaldi), or a technical analogy (cable
chain, which looks like an anchor chain).
Chain making at Uno-a-Erre's
factory in Arezzo, Italy
(Credit: courtesy Uno-a-Erre)
Hand finishing at Uno-a-Erre's,
Italy's largest maker of chain
(Credit: courtesy Uno-a-Erre)