From ICC 400-2007, Standard on the Design and Construction of Log Structures.
I think what he needs is under "Mixed Oak". TP is the listed grading
rules authority, For logs there are only 2 authorities, them and the
Log Homes Council. Any accredited agency can grade, according to the
grading rules written by these two rules writing authorities. TP has
an office and graders in WA;
http://www.tpinspection.com/Under their designation "SRTB" sawn round timber beams.
Mixed Oak
Unsawn- Fb1900, Ft1050, Fv170, Fcperp820, Fcll900,E1.2
No 1- Fb1550, Ft850, Fv170, Fcperp820, Fcll750, E1.2
No 2- Fb1300, Ft725, Fv170, Fcperp820, Fcll625, E1.2
No 3- Fb750, Ft400, Fv170, Fcperp820, Fcll350, E1
An SRTB can have no more than 3/10 radius sawn or shaved from 1 face
only, no more than 1/8" taper per foot.
If the log needs to be worked more than that it becomes a Wall Log.
The largest inscribed rectangle is drawn on the cross section and that
section is the beam.
A premium mixed oak wall log begins at Fb 1250, the wall log grades
end with Wall Log 30 at Fb550.
For a rectangular sawn timber refer to the NDS. Mixed oak Select
Struc, the best sawn timber, Fb1100, the unsawn round timber was
Fb1900.
Take care,
Don