3 ms·
The US units are defined in terms of SI since the Mendenhall Order[0], so they also benefit from this change. [0]: https://en.wikipedia.org/wiki/Mendenhall_Ord
by clord 8y ago
The US units are defined in terms of SI since the Mendenhall Order[0], so they also benefit from this change.
[0]: https://en.wikipedia.org/wiki/Mendenhall_Order https://en.wikipedia.org/wiki/Mendenhall_Order
- kevin_thibedeau 8y agoIt wasn't until 1959 that the yard was metricized. This still affects precision machinery manufactured before the changeover.
- clord 8y agoIt was metricized with all the rest before that. What happened in 59 was harmonization with other countries including Canada, who had a different agreement on the metric yard. The older american definition was 1 yard = 3600/3937 meter. The international metric yard is exactly 0.9144m. (A difference of 0.002mm)