6
are of the jig type, and incorporate two or three flush pin plugs to check the relationship of various surfaces on
odd-shaped pieces. All kinds of Go and Not Go snap gauges are made up. There are complete facilities for check-
ing gauges, including protection apparatus.
Gauge Control
Gauge control is exceedingly important in a plant such as this one, manufacturing interchangeable parts. A sepa-
rate department had been set up to control gauges and gauge tolerances have been established independently,
although necessarily in line with government standards. As experience is built up in actual inspection work, the
frequency with which working gauges are brought into the gauge laboratory for recheck is revised from time to
time. Obviously, some gauges wear rapidly and others last much longer, depending upon the application and
gauge tolerance.
As on all government Ordnance work, the unilateral system of gauge tolerances is followed, that is, the limits on
the work encompass all gauge tolerances. In other words, all high-limit gauge tolerances are negative and all low-
limit gauge tolerances are positive. The gauge tolerance for a Not Go plug is always taken on the negativf,side,
for example and on a Not Go ling gauge on the positive side. In commercial work the tolerance zone on the
gauge more often is centered about the upper or lower limit on the work. Ordnance engineers contend that the
unilateral system is more scientific than the commercial, bilateral system, and more positively assures the produc-
tion of interchangeable parts.
Aside from process inspection throughout the plant, there is a final inspection area under a different head to assure
interchangeability of parts. This final inspection is independent of U.S. Ordnance inspection which gives a further
check. Both plant inspection supervisors report to the production managers. Incidentally the supervisor of the tool
and gauge department reports directly to the works manager and as far as the production department is concerned
this tool department acts as an outside supplier. Final inspection of the product after assembly includes proof
firing to test for proper functioning of the gun and a test for accuracy of fire in a machine mount.
Acting as an outside supplier would not be hard to do for a separate company.
By 1942, the Tool Division, as it was now called was moved to Greenwich, Conn. and combined with other
Maguire companies into a new facility at 342 West Putnam Ave. This is further described in the book Tommy by
Frederic Willis:
AUTO-ORDNANCE GREENWICH, CONN Research and Development
On May 1, 1942 your company leased a building consisting of 30,000 square feet at Greenwich, Connecticut, for
its research and development laboratory. The building was promptly revamped and equipped into a modern
research and development laboratory. In September, 1942, the space was increased to 45,000 square feet by the
construction of a third floor. The work was departmentalized into the following categories of operation: Ordnance
Division, Electronics Division, Thompson Tool Division, Food Processing Division and Chemistry Division, with
adequate facilities for drafting rooms and administration.
The Thompson Tool Division has been fully set up and in operation in the Greenwich plant since September, 1942
and has not only continued to supply Bridgeport with some of the necessary cutters, gauges and fixtures
for gun manufacture, but has accomplished creditable results in the completion and sale of manufacturing fix-
tures to other companies (including our subcontractors) engaged in war work.
In general, the work of the Research and Development Department in the future will be largely directed towards
the objective of completing the development projects already instituted and commercializing the resulting prod-
