jonmac wrote:
>
> Sadly, this doesn't work quite
> so well in working out the nearest equivalent to a 5/16 or
> a 17mm spanner - but I'm working on that.
1/16" to mm is pretty easy, just add 50%. IOW to convert 5/16" to mm,
add 1/2 of 5 to 5, to get 7.5mm (pretty close, actual value is
7.9375mm).
The other way is a little tougher, but 2/3 of the value in mm is a
little over the value in 1/16". So, to convert 17mm in my head, I first
double the 17 (=34) then divide by 3 to get 11/16" (actual conversion is
.669" or 10.5/16").
Or, to get the decimal value in inches, multiply by 4 then divide by
100. 17 times 4 is 34 times 2 is 68, so 17mm is .68" .
Randall
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