Percentage overrun from three log rules (Doyle, Scribner Dec. C, 

 and International ^-inch) is shown in table 5. Although limited in basis, 

 the overrun data are representative for the given range in log size. 



Table 5 .- - Percentage overrun from three scale rules for hickory,-^ Indiana 

















Log 

 d.i.b. 

 (inches) 



Average percentage 



overrun 



from-- 





Basis 



Doyle 

 rule 



Scribner 

 Dec. C. rule 



Internat 

 (i) ru 



ional 

 le 



(logs) 



11 



82 



49 





18 





1 



12 



67 



40 





14 





2 



13 



54 



33 





12 





5 



14 



44 



27 





10 





7 



15 



36 



22 





8 





4 



16 



30 



19 





6 





5 



17 



25 



15 





4 





2 



18 



20 



12 





3 





2 



19 



16 



9 





1 









20 



12 



6 











2 



21 



9 



3 





-1 





1 



All sizes 



31 



18 





6 





31 



J/ Original data collected by Purdue A.E.S. Based upon 4,390 board-feet, 

 mill tally, of sound logs only. 



Volumes of trees in handle bolts and added saw log-volumes are shown 

 in table 6. The scale of bolts is shown in both board- feet and in total inches 

 of diameter (inside bark) at the small end of the bolts. Standard bolt length 

 is 40 inches, and the minimum top diameter is 7 inches. 



GRADING OF TREES AND LOGS 



Two sets of log grading rules are presented. The Purdue grades define 

 quality by reference to the proportion of the "cylindrical" segments of the log 

 that are clear of external evidence of defect. The Forest Service Standard 

 Grades for Factory Logs (table 7) are based upon the amount and length of 

 "clear cuttings" on the three best "grading faces." As with log rules, these 

 grades are not specifically for hickory logs, but were designed to be applied 

 generally to all species of hardwoods. 



