333 Spencer Street

IN passing through tho well-built modern factory of John J). Arnold. Pty. Ltd., manufacturers, of. paint-spraying equipment, at 333 Spencer street, the visitor is left with two impressions.

The first is one of scrupulous cleanliness, the second of hairbreadth accuracy. Here are machines which could, if you wished, record and duplicate the finest of human hairs. One machine in particular, Illustrated here, holds the visitor’s attention. Its function is the production of the delicate parts of tho spray gun.

A nipple machine at the Arnold works, incredibly precise in operation. of the “Arnold” equipment, which is revolutionizing painting in Australia. Tho material nipples of the spray gun are made from steel stock on this very ingenious and extremely accurate machine. The tolerance allowed on four of the dimensions of the nipple are less than one-thousandth of an inch. To realise this accuracy the layman must, compare a human hair, which is three-thousandths of an inch. There parts are then hardened-and heat treated, when minute accuracy tests take place. Every nipple has to pass an actual spraying test before it is released from tho factory. With the product of this ingenious machine, as with that of every machine in the shop, extreme accuracy is first proved by the use of go-and-no-go gauges. Then comes supervision by inspectors, whose solo job is one of exacting and continuous testing to ensure that only the accurate reach the assembly line. This accuracy, coupled with the quality of material and workmanship and backed by scientifically perfect findings and formulae, not only belongs to the paint-spraying equipment but typifies every “Arnold” product. Other products of this all-Australian plant which have meant much to the progress of engineering in this country include such well-known items as the’ “Arnold” oxy-aoetylene equipment, compressed gas fittings and dissolved acotyleno plant. Messrs John B. Arnold Pty. Ltd. are to be congratulated on their products and standing. It Is such progressive firms as this that spell suprmacy for the Australian engineer.