On 26/06/2017 3:40 AM, John Ruth asked:
> How do metric countries handle this?

Well, in this metric country (Australia) exact section sizes (rather 
than nominal sizes) are part of the description (measured in millimetres).

In our system, logs are rough sawn to standard sections in 25mm steps -- 
25, 50, 75, 100 etc (which correspond to your 1, 2, 3, 4 inch steps). 
Plus a few intermediate steps, such as 38mm (inch-and-a-half). 
Acceptable tolerance is plus or minus 3mm (eighth-of-an-inch).

Timber that is sold seasoned and dressed is described by the actual 
dimensions -- so a stick of plantation-grown pine that started as a 
75x50 is sold as a 70x45.

Peter Marquis-Kyle
A fan of the millimetre