It is a 3/64" hex wrench on my HRO-50,
I assume unchanged on your HRO-60.

73,
Ed Knobloch

Hi Ed,

just a curiosity.

In Europe the hex wrench and spanner size varies in increments of 0.5 mm (a
little more than 1/64"). We then have wrenches of 0.5, 1.0, 1.5, 2.0, .... Very
easy.

In the US, instead of always expressing size as multiples of 1/64" (that is
1/64", 2/64", 3/64", 4/64", 5/64" ...), when possible you simplify the fraction
(that is 2/64" -- 1/32", or 16/64" -- 1/4"). I wonder whether the average
AmerIcan, not necessarily well accustomed to play with fractions, can instantly
determine that, if e.g. a 17/32" spanner is too big, he should try a 33/64"
spanner before taking a 1/2" spanner.

73

Tony I0JX, Rome Italy