Solid Wood Products 2567 



Table 22-6 — Average lumber recovery values from sawlogs of six hardwood species and 

 three log grades in the Appalachian region during J 955 and 1964 (Martens 1967) 



Species groups and log grades 1955 1964 



-Dollars per thousand hoard feet of lumber sawn- 



Ash 



Log grade 1 133 148 



Log grade 2 102 ill 



Log grade 3 75 79 



Hickory 



Log grade 1 78 90 



Log grade 2 59 69 



Log grade 3 46 49 



Soft maple 



Log grade 1 119 149 



Log grade 2 103 130 



Log grade 3 75 89 



Red oak 



Log grade 1 130 135 



Log grade 2 93 92 



Log grade 3 68 65 



White oak 



Log grade 1 141 146 



Log grade 2 95 92 



Log grade 3 70 66 



Yellow-poplar 



Log grade 1 128 133 



Log grade 2 98 105 



Log grade 3 75 -80 



Planing of lumber is described in figures 18-138 through 18-144 and in 

 sections 18-4 through 18-7 and 18-13; for procedures to control planing defects, 

 see text related to tables 18-32 through 18-35. 



What future developments are likely in the manufacture of hardwood lumber? 

 Because of the skill required and labor cost to visually grade lumber, it is 

 possible that the process will be computerized. Also, decreasing availability of 

 high-quality sawlogs may cause mills to laminate hardwood lumber to obtain the 

 sound furniture cuttings needed. 



Grading lumber by computer. — The mathematical basis of the grading 

 system of the National Hardwood Lumber Association involves estimates of the 

 amount of clear cuttings available from each board. To group boards into grade 

 classes with similar proportions, the grading rules prescribe minimum width and 

 length, maximum wane allowance, maximum knot size, and extent of splits for 

 each grade. Grading also requires decisions on ripping to two boards of differing 

 grades with more value than the single board. 



Decisions made at edger and trimmer are largely two-dimensional, involving 

 length and width. Hallock and Galiger ( 197 1 ) described the problems associated 

 with making two-dimensional decisions as requiring development of a computer 

 program using the description of a flitch or board as input; as output, the 



