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1988 560SL (California Model)
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5,074 Posts
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For those not familiar with Starrett it is a US based company known for their high end (and very pricey) measuring equipment. Think machinists...tool and die makers...probably even some labs where length/depth measurement is critical. Found these decimal equivalent/metric equivalent charts there for download.

The one named “wall chart” will probably need a special printer or downsizing. Dimensions of the chart are 25” x 39” or 635mm x 990mm.

The two named “card” print out 3” x 5” and are meant to be clear-plastic laminated so they would end up about 4” x 6”. Also each “card” file has 2 pages.

2612574
 

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1987 560SL (L.Tonk) [92,700 miles]
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245 Posts
I found out recently that the inch was originally defined as the length of 3 "average" barleycorn. It then had varying official lengths in Europe, UK, and USA until the 50's when precision manufacturing necessitated a common and exact measure, which ended up being 25.4mm exactly, meaning the whole of Imperial/US length units are metric based. The exception is in US Survey data, which uses the old US measure which differs in about 1" every 8 miles.
 

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Registered
1988 560SL, 1969 280SL(113)
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105 Posts
I found out recently that the inch was originally defined as the length of 3 "average" barleycorn. It then had varying official lengths in Europe, UK, and USA until the 50's when precision manufacturing necessitated a common and exact measure, which ended up being 25.4mm exactly, meaning the whole of Imperial/US length units are metric based. The exception is in US Survey data, which uses the old US measure which differs in about 1" every 8 miles.
"Use of the inch can be traced back as far as the 7th century. The first explicit definition we could find of its length was after 1066 when it was defined as the length of three barleycorns. This was not a satisfactory reference as barleycorn lengths vary naturally. The British Standards Institute defined the inch as 25.4mm in 1930 in the document "Metric Units in Engineering: Going SI". In March 1932 the American Standards Association were asked to rule on whether to adopt the same value (at the time the American inch was 1/.03937 mm which approximated to 25.400051 mm). Because the values were so close, and because Britain has already settled on that value, the ASA adopted this value on March 13, 1933."
 
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