Tree and Log Scale Stick

Used to determine board footage of standard timber.

The 62D, 62I and 62S Tree and Log Scale Stick are used for diameter measurements for dbh, determining merchantable tree height, finding volumes for standing trees (FC 78) and finding volumes for bucked logs. Available in Doyle, Scribner and International scales.  All Tree sticks are Form Class 78 (FC 78).

Doyle Scale, International Scale and Scribner Scale Described:

Doyle Tree & Log Scale Stick: Based on the algebraic equation: bd ft = [(D-4) / 4]² x L. D represents the log diameter in inches and L represents the log length in feet. The Doyle Scale has a slab allowance of 4" and a saw kerf of 5/16" or 25%.

Scribner Tree & Log Scale Stick: Based on diagrams of 1" boards drawn to scale within different sized cylinders. The saw kerf is assumed. to be 1/4". However, the minimum board width allowed is not clear but may have been 4" for some log diameters. All volume outside scaling cylinders projected from small ends of logs is ignored, since no taper allowance was included.

International 1/4" Tree & Log Scale Stick: Derived from the mathematical formula: 0.905 )0.322 D2- 0.71 D). Volumes for 16' log lengths require an easier formula: 0.8 (D-1)2. This is the only commonly used scale that allows for log taper. The fixed taper allowance is 1/2" per 4' log length. Scale values for a 16' log are obtained by adding board foot volumes of four 4' cylinders, each 1/2" larger in diameter than the previous log. Rational deductions for slabbing saw kerf are also included. The International 1/4" Log and Tree Scale Stick has a 1/4" saw kerf plus a 1/16" allowance for board shrinkage, providing a total deduction of 5/16" Slabs are deducted in the form of a hypothetical plank 2.12" thick with a width equal to the log diameter. All logs are considered to have been cut into boards 1" thick