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Ford Motor Company’s switch to metric

Ford Metric Steel

Ford Motor Company’s switch to metric

From the May/June 2017 issue of USMA’s Metric Today.

by Don Hillger

In 1971, Ford announced plans to produce a metrically-designed four-cylinder engine for its Pinto model. This was the first production engine designed and built in the US that made complete use of metric engineering standards and achieved compatibility of parts with the four-cylinder engines produced in Ford’s British and German companies. That 2.4 L engine first appeared in production in the 1974 Pinto.

That was the first example of Ford’s policy to use the metric system as the predominant method of measurement. North American Operations began a coordinated conversion to the metric system starting with the 1978 model vehicles. Ford established a formal corporate metric conversion policy, announced at an annual stockholder’s meeting by Henry Ford II, Chairman of the Board for Ford Motor Company. (Ford’s policy was to increase use of the metric system and at the same time minimize incremental costs of conversion, to tool parts and systems in metric measurements as new designs justify the changeover.) Ford expected to be predominantly (more than 50%) SI metric after 1985 for North American vehicles. That was an increase from only 20% metric content in 1980.

Portions of Ford’s metric policy included:

  • New vehicle systems and component designs were to be metricated
  • Every opportunity should be taken for using metrication to simplify and commonize products and specifications
  • Metrication is to be achieved at minimum incremental cost
  • Future metrication needs should be anticipated in the specification of equipment, gages, tooling, materials, technical references, and supplies
  • Exceptions to this policy must be justified on the basis that a future metrication will be less expensive than the scheduled metrication

According to Ford officials, anticipated problems in metric production did not materialize. The chief problem was educating suppliers, and to do that they prepared a manual of specifications on tools such as taps, dies, etc. No new training was required for semi-skilled workers on the line. The skilled tradesmen, jobsetters, and engineers had no problem with metric working.

Ford worked with Chrysler and General Motors to set new standards for stamping design, specification, and construction in the car industry. These standards are known as the North American Automotive Metric Standards (NAAMS). NAAMS commonized and reduced the number of components and tools used by the auto industry. Also identified were other metric standards (for use in design and construction) that were issued by recognized standards groups such as ANSI, DIN, and ISO. This resulted in suppliers not having to maintain as large an inventory compared to what had been required in the past. Auto industry use of the new standards allowed interchange of components from different suppliers, and eliminated the need for the buyer to have to re-machine components bought from different suppliers.

At the same time that Ford’s automobiles started their switch to metric, their tractor and equipment plants also underwent a comprehensive program to introduce metric to facilities and employees.

Ford’s metrication policy stated clearly that All industrial nations are using or are converting to the metric system; continued use of two measurement systems in worldwide multi-national operations is incompatible with Ford’s basic objectives; we are implementing a minimum cost transition that may continue into the 21st Century. Ford saw the obvious efficiencies of converting in their statement that, “We endeavor to get as much commonality as possible, given our differing market requirements and suppliers.