Spahr Metric Metal

421 McGhee Road
Winchester, VA 22603

Metric at John Deere and Company

John Deere has been using metric metal since 1962.

As far back as 1962, (John) Deere and Company considered universal production designs with worldwide application. At the time, factories in metric countries had to convert inch-based drawings, which meant rounding off numbers. In redrawing, not only is there a waste of time, but mistakes are likely, and there is a real chance of costly errors.

At first Deere used dual dimensions on all drawings, so the same drawings could be used with metric or non-metric parts. However, close tolerances on parts meant that metric and non-metric parts were generally not interchangeable, so maintenance could be tricky and warehouses had to stock twice as many kinds of parts and materials. Although that burden would diminish as metric modules took over, dual dimensioning was not the answer.

The solution was to change to a single (metric) system on all new designs, starting with what they called a clean sheet of paper. International designs were first to go metric, but US factories were eventually scheduled for conversion. The goal was to use the same system worldwide. This would eliminate a great deal of confusion and eliminate the additional work of dual dimensioning.

For fasteners, Deere initially stayed with unified (inch) threads because metric fasteners were not widely available in North America. But as metric fasteners became more common, Deere adopted increasing numbers of metric sizes, with the goal of using only one fastener system. As a result, Deere became an industry leader in the use of metric fasteners and in the development of fastener standards and preferred sizes.

Immediately converting drawings to metric-only measurements would have incurred up to a 15% cost penalty from some tool suppliers, as well as the possibility of conversion errors by suppliers not yet ready for the transition. Therefore, Deere initially provided inch equivalents in a corner of each drawing as a way to eliminate outright dual-dimensioning. While Deere did not force metric on users of its drawings, its actions encouraged metric usage.

Training in the metric system was essential, although not overdone. Engineers were trained first, then foremen, and others as the need arose. Training was proportional to the use of metric measurements, and workers were already familiar with decimal measurements—Deere had changed from fractions of inches to decimal inches in the 1930s, as precision manufacturing increased and they realized that decimals were much easier to add—so the transition from decimal inches to millimeters was relatively easy.

In the specific case of a complete moldboard plow line that is all metric, changing to SI did not cost Deere any additional money because the switch to metric was implemented at the same time that model was redesigned and retooled. In another example, Deere saved $380 000 when it converted to metric-sized sheet steel in constructing its combines.

In marketing areas, Deere was more cautious. It decided not to promote the metric system as a sales feature, but some metric informational programs were provided based on dealer and customer needs. (Unlike cars, where buyers typically never knew their new cars were metric, customers for Deere’s machinery were more likely to have a “hands on” relationship with the machinery.)

In summary, Deere stressed the long-term advantages of the metric system, giving its suppliers the option to see that “metric makes sense”. Deere’s metric conversion committee provided guidance and coordination so that intermeshing metric activities stayed in step. All factories and activities were part of a well-planned and orderly company-wide transition led by corporate headquarters. The target date of 1978 for complete communications capability in SI resulted in a universal set of specifications and a common measurement language for its worldwide operations.

As a footnote, in 2007 the author visited Deere’s tractor assembly facility in Waterloo, IA. Although the tour guide used both metric and non-metric units in describing various activities, it was clear that the company was primarily metric and that metric fasteners were in use. Since a large portion of Deere’s sales are destined for foreign markets, this is an extra incentive to go metric. As an example, the speed limits for various models destined for Europe are clearly displayed as required in kilometers per hour on the rear of the tractors to be exported.

Note: Material for this article came from various articles written about the Deere and Company’s conversion to metric, both in the published literature and past metric newsletters.