Solid Wood Products 2663 



Table 22-17 — Comparison of cant volume and 414 lumber yield that can be sawn from 

 12 -foot-long cants of various end dimensions (Niskala and Church 1966)' 



Cant end 4/4 Proportionate 



dimensions Cant lumber Volume volume increase 



(inches) volume yield difference from cants 



-Board feet Percent 



4x4 16.0 12.0 4.0 25.0 



4x5 20.0 15.0 5.0 25.0 



4x6 24.0 18.0 6.0 25.0 



5x5 25.0 15.0 10.0 40.0 



5x6 30.0 20.0 10.0 33.3 



5x7 35.0 25.0 10.0 28.6 



6x6 36.0 24.0 12.0 33.3 



6x7 42.0 30.0 12.0 28.6 



6x8 48.0 36.0 12.0 25.0 



7x8 56.0 42.0 14.0 25.0 



7x9 63.0 45.0 18.0 28.6 



8x8 64.0 48.0 16.0 25.0 



'Based on l-'/s-inch-thick 4/4 hardwood lumber sawn with V4-inch kerf. 



The size timber obtainable from a log is related to both log diameter and 

 sweep (fig. 22-51), and is therefore related to log grade. Considering mill-run 

 diameters of Grade 3 logs cut from Appalachian red oak, white oak, and 

 hickory, Garrett (1969) found that only 12 percent would yield 10- by 10-inch 

 timbers, but 76 percent would yield 4 by 6's (fig. 22-52). When sawing 6- by 8- 

 inch and 7- by 9-inch timbers from mill-run logs. Church and Garrett (1970) 

 found that the percentage of logs yielding such timbers varied not only with log 

 diameter but also among species (table 22-18). 



Garrett (1969) concluded from his study that when markets for sawn timbers 

 are available, the combined production of lumber and timbers from physically 

 suitable logs will give greater dollar return than production of lumber alone. He 

 further concluded that mill operators who engage in the dual production of 

 lumber and timbers must carefully direct log-bucking and sawing practices to 

 provide maximum income. If logs are bucked to conform to sawn-timber 

 lengths, then potential dollar yields from high-value side lumber are sacrificed 

 because of the preponderance of short boards. Conversely, if logs are bucked to 

 produce long high-grade lumber, then overlength waste blocks from timbers 

 reduce volume yield and dollar income. There is no perfectly satisfactory solu- 

 tion. However, when a sawmill operator has a choice, he should saw timbers 

 from those species and log grades that normally would give him the lowest 

 hourly return if sawed exclusively into lumber. 



Putnam's (1959) analysis of dollar returns from southern oaks and gums cut 

 for lumber alone or for lumber plus railroad timbers supports Garrett's 

 conclusions. 



