In
the manufacture of many rings, the metal first receives a special form.
The gold plates are blanked and rolled to a definite thickness
according to the pattern of the ring desired, the width being
controlled by screws attached to the rolls themselves. To obtain the
exact width, the measure in which it is placed can be adjusted to cut a
strip of metal from a millimeter, or thinner, up to several inches in
width. It is slid over a roll and two wheels with sharp edges separate
the mass of gold into exactly the desired widths. The gauges are so
exact as in one instance to provide 16 variations to a millimeter,
approximately 1/25 of an inch. Another screw gauge is so delicate that
it can be adjusted to the four-thousandth of an inch.
Each
piece is then put in a cutter exactly the outline of the desired piece,
which, for a ring, is usually quite flat. The piece of metal then drops
into a cutting box and a number can be struck out successively by
simply raising the press and allowing the cutter to come down. The
metal is now placed in another roll, which, in the case of the signet
ring, rolls the sides thinner than the head. When this process is
completed the product is put in a gauge measure which measures the
length of the ring from 0.4 to size 13, on Allen's standard gauge. The
ends of the metal are then cut off so that the ring is approximately
the desired size, and the ends are annealed or soldered without any
further operation.
In
most cases when striking a signet-ring, the top is not cut out
entirely. The gold backing of the stone is left, and the head of the
ring is struck with a concave space so that when the two sides are
brought down the space will remain flat. For transparent stones, the
top is cut out of the setting entirely. When the rings are finally
completed they are cleaned by what is known as
