Posted by Michael Gilligan on 19/07/2020 08:51:48:
Please forgive the digression, but I was intrigued by that 46.3mm dimension
46.3 ÷ 25.4 = 1.82283464566929 [which doesn’t look very encouraging]
and [using the converter on ‘calculator soup’] the fractional value is
1.8228346456692 = 1 + 2057086614173 / 2500000000000
[and rounding-up doesn’t seem to improve things]
Google search for 46.3mm finds a Trend router cutter of that diameter, but little else of interest
Eureka !
Somehow, I managed to stumble into: **LINK**
http://www.convertaz.com/convert-cable-length-(international)-to-kilofoot/
Which reveals that:
3 cable lengths (International) = 1.8228346457 kilofeet
.
Now, can someone [probably Dave S.O.D.] please explain the connection between that little gem and the A/F dimension that MCB measured ?
MichaelG.
I'm baffled.
A cable is 1/10th of a Nautical Mile, defined as 1 minute ( ie 1/60th a degree) of latitude along any line of longitude, which are approx 40000km in circumference. And the nautical mile is derived from the 1791 metre, which is one ten millionth of 90° of latitude along any line of longitude, ie approx 10000km. So a nautical mile is 1852 metres, making 3 cables 617⅓ metres, or 1822.8346457 feet
Never heard of a kilofoot before, but its real (304.8m).
Reckon I'm completely bamboozled by numbers matching randomly as necessary to draw Ley Lines and the answer is nothing to do with units. Is it that kilofeet are used to measure telecommunication cables, as in “When arranged in this way, the cable exhibits a nominal resistance of 0.067 ohms per kilofoot of phase.” and that cables are often run over floors in houses, offices and flats? (Across Flats, geddit!)
I was going to suggest MC's 46.3mm measurement is actually 1 53/64" or 1.8203125" But 1 53/64" isn't a standard spanner size. Maybe chuck flats aren't standard? Those on my ER32 chuck are 35.15mm, which is also weird. I made a spanner to fit and labelled it 36 though its actually 35.85mm

The spanner doesn't need to be strong. This one has a mild steel head bolted into an aluminium handle with an M6 Allen Bolt – junk box metal and rough craftsmanship.
Dave