University of Wisconsin Digital Collections
Link to University of Wisconsin Digital Collections
Link to University of Wisconsin Digital Collections
The University of Wisconsin Collection

Page View

Hartnell, June (ed.) / The Wisconsin engineer
Volume 49, Number 8 (April 1945)

Dickenson, E. H.
Wire gages,   p. 10


Page 10


WIRE
GAGES
-E. H. Dickenson, e'43
O RDERING WIRE was not always the simple matter
   that it is nowadays. Years ago the existence and usage
of many types of gages caused great confusion in the de-
termination of wire sizes. For instance, many wire manu-
facturers r e c e i v e d orders for wires and didn't know
whether the size referred to the Birmingham Wire Gage,
the British Standard Gage, the American Wire Gage, or
one of the 40 or more existing gages. And even if the
manufacturer had known the gage desired, there often was
such a difference between copies of gages of the same type
that it was likely that the wrong size would be sent to the
customer anyway.
  This deplorable state of affairs was recognized by all
concerned with the use and manufacture of wire and
efforts were made to eliminate the confusion. In 1879, a
committee of the Society of Telegraph Engineers in Great
Britain investigated the wire gage question with the in-
tention of deciding upon a standard gage. Many satisfac-
tory gages had been developed, but difficulty arose be-
cause no gage was universally used.
  The committee suggested that the gage to be adopted
as a standard should not differ greatly from the gages
then in use under the name of Birmingham Wire Gauges
since these gages had been based on and experience were
well adapted to the practical requirements of trade.
  Though the B.W.G. (Birmingham Wire Gauge) was
used extensively, it could not very well be adopted for a
standard gage because there were variations in the B.W.G.
gage itself as used by various agencies. The Board of
Trade in Great Britain was seeking information on the
gage question and in the 12th Annual Report to Parlia-
ment on Standard Weights and Measures for 1877-78, the
Warden of the Standard stated that there was no standard
of the B.W.G. gage or no agreement between parties as to
sizes, as they were not geometrically or arithmetically pro-
gressive and bore no relation to each other. The origin of
the B.W.G. was clouded, but it seemed that as new sizes
were needed or some new plate introduced, several sizes
would appear with no relation to each other, resulting of
course in annoyance and pecuniary loss to contractors
using such a gage.
  Mr. Latimer Clark, Mem. Inst. C.E., had suggested that
the sizes of the B.W.G. were first arrived at by taking a
series of already drawn wires and constructing the gage
directly from those since "at the time from which the
Birmingham Wire Gauge probably dates, the manufac-
turers who then introduced and employed it were not, I
think, of a class likely to call in the aid of either mathe-
matical or physical s c i e n c e to supply them with the
ground-work of a gauge."
  Wire manufacturers probably provided themselves with
a gage such that the largest wire they could draw would
be termed No. 1, the next largest No. 2, etc. Thus a thor-
oughly practical gage was established. The fact that in
the B.W.G. existing in 1879 there was a fairly constant
relation between the weights of each size of wire (about a
20'/, difference) also indicates that this was the origin
of the B.W.G. because the constant reduction in weight
would have been most suitable in practice especially before
the introduction of steam power.
  On the basis of practicability then, the B.W.G. was the
best suited for recommendation as a standard gage. Its
big drawback, though, was that it was an empirical gage,
one in which the graduations between respective sizes
were formed by arbitrary differences. The geometric gage,
would without a doubt, h a v e the advantage of being
formed by perfectly uniform increments or decrements
of weight from size to size, the difference being the same
in the smaller sizes as in the larger ones.
  Investigation found two suitable geometric gages, the
American or Brown & Sharpe Wire gage and the Clark
gage. The American Wire Gage was rejected by the com-
mittee because its sizes differed widely from the Birming-
ham Wire Gage sizes. But the C 1 a r k gage conformed
closely in sizes with the existing B.W.G. and consequently
the committee recommended it to the Society of Tele-
graph Engineers for adoption as a standard gage. It was
proposed that a distinctive name, such as the British
Standard Gauge (B.S.G.) be given to the Clark gage.
Since the existing gages differed only slightly from the
one being introduced as a standard, it was felt that no
great inconvenience would arise. "Tables of weight or
wire and sheet for different metals would become possible
and would enable any of the sizes to be bought and sold
by weight, or by the thickness checked by their weight.
Concurrently with this, the system of measurements by
thousandths of an inch will be available as heretofore . . ."
  This attempt of the Society of Telegraph Engineers
                 (please turn to page 18)
THE WISCONSIN ENGINEER
10


Go up to Top of Page