The Dockwra Works specialized in the manufacture of brass pins. Their brass was 'passed between stones in order to beat out a plate of about 70 lb weight. This was cut into seven or eight strips, then stretched on the rolling mill operated by water power to the designed thinness and periodically annealed. The resulting sheets were then cut into many long threads and drawn into wire of the required sizes. The wire was cut into lengths of 5 or 6 yards and then into 6 inch or 8 inch pieces. The end was pointed on a machine and the wire cut off to the length of the pin; heading was done by stamping. The pins were then tinned and packed. Each of these operations was performed by a different workman and it was said that the best workmen could deal with 24,000 pins a day.' (22)
Other firms sold the long strips of wire for working up elsewhere.
The pin-making trades were centred mainly in the Birmingham district, along with brass founding for the manufacture of thimbles and similar items; others were near London, at Islington and Highgate.
Towards the end of the 18th Century, as more complex designs developed, the pumps employed in the mines and elsewhere required a steadily increasing number and variety of steam valves, safety valves, cocks, taps, flanges and similar parts, mainly in brass. By about 1770 all these things were being manufactured in the Midlands, besides greasecups, gauges, whistles, pump cylinders, candlesticks and brassware generally.