Propeller roughness definitions

Hello...

Can anyone point me to a reference to correlate "equivalent sand roughness"
(as used by the ITTC-78 propeller scale correction) to contemporary
propeller manufacturing practices? (Something like: a typical hand finish is
equivalent to XX micrometers in equivalent "sand roughness"; CNC is YY
micrometers; polished is ZZ micrometers?) What is the roughness of the best
commercial finish (polish)? How does this relate to other measures, such as
the Rubert propeller roughness gages?

Regards,

Don

Donald M. MacPherson
VP Technical Director
HydroComp, Inc.
email: dm ~ AT ~ hydrocompinc ~ DOT ~ com