26 DECEMBER 1941, Page 11


SIR,—After two years as honorary secretary to one of the earliest- formed groups of small manufacturers, I agree very largely with your cogent article of the 12th instant. The Regional Boards are doing a good job, but in place of their present rather nebulous character some more unmistakable authority would no doubt greatly help efficient production.

There are, however, two practical points which are really serious deter- rents, especially concerning the so-called " small " firms, (a) excessive and expensive inspection and stamping of details, and (b) unnecessarily fine accuracy. As to the first, work is often held up in intermediate stages awaiting the inspector's visit to pass and stamp sometimes thousands of details of a quite ordinary quality. Some responsible person must be in attendance and cost is added appreciably But the second point is even more important. The small firm's easy quality of work has in many cases become a tradition with them, and tradition is a hard and almost inexorable taskmaster. Only a violent wrench will transfer these firms from the comfortable footrule toler- ance of a sixty-fourth of an inch to the micrometer, with its " thou " (workshop shorthand for " thousandth of an inch "), or its half-thou. Not only is the micrometer largely unfamiliar, but the machine tools are often not in a good enough condition to produce the required accuracy.

Such firms are frightened by the demand and ask, " Are these fine limits necessary? " An honest and informed answer would be that in possibly half the cases they are not, and that they retard produc- tion to an incalculable degree. Few designing draughtsmen seem to know that it may take twice as long to work to a tolerance of one thou instead of three, and at least five times if the tolerance is reduced to half a thou. Recently the writer saw a large but flimsy brass detail which when inspected had to be within limits so fine that the change of temperature in the workshop throughout 24 hours caused the detail to expand and contract beyond the required allowance. " And," said the disgruntled works manager, " when all is said and done the damned thing only has to fit water! "

I believe nothing would so beneficially and immediately affect pro- duction as the institution in the drawing offices concerned of a know- ledgeable censor of detail-drawings before their issue, so that he could allot reasonable tolerances appropriate to requirements, choosing always the widest permissible. Such a censor could do much good time- saving work in other directions, but the greatest economy would be in the modification of often senselessly fine accuracy. This modifica- tion would be welcomed by all firms, large or small, and certainly without it the small ones cannot be fully used.—Yours faithfully,


Peterborough and District Manufacturers' Wartime Alliance, 5 The Precincts, Peterborough