3294 Chapter 27 



Yield of dimension stock from bolts and short lumber. — In general, the 

 yield of furniture cuttings from short lumber ranges from 70 to 85 percent; the 

 yield from comparable lumber of standard length runs 60 percent (Bingham and 

 Schroeder 1977). 



One reason for the greater yield from short bolts is that the effects of crook and 

 taper can be minimized when tree stems or long logs are cut into short bolt 

 lengths before processing. For example, in a study of red maple logs from 

 Florida, Huffman (1973) found that 4-, 5-, and 6-foot bolts produced more 

 lumber and furniture cuttings than standard-length logs (fig. 18-113). The over- 

 run for green lumber tally was about twice as much with bolt sawing as with 

 conventional sawing, and the bolts produced a 16 percent greater yield of 

 furniture cuttings than the sawlogs (table 27-116). The small, low-grade logs 

 showed the greatest increases in yield. Large logs showed less increase, but 

 because of the greater volumes of wood involved in the larger logs, even a small 

 percentage increase may be worthwhile. 



In a North Carolina study, bolter sawing 4- to 6-foot red oak logs with a total 

 volume of 2,560 bd ft (International V4-inch rule) produced a lumber tally of 

 2,850 bd ft — a 13 percent overrun (North Carolina Forest Service, no date). 

 Lumber graded No. 3 A common and better comprised 51 percent of the board- 

 foot- volume; the rest was No. 3B common suitable for pallet stock. The number 

 of clear faces on the bolt was highly significant in determining the quality of the 

 lumber sawn (table 27-1 17). Bolts with two or more clear faces produced 72.6 

 percent of the No. 1 common lumber and 40.6 percent of the No. 2 common 

 lumber, the grades usually considered necessary for furniture dimension stock. 

 Bolts with one or zero clear faces produced more No. 3B lumber than No. 3 A. 

 Yields of clear-two-face furniture cuttings were as high with this short lumber as 

 with standard length lumber of the same grade. The yield from No. 3 A lumber 

 was 48 percent, suggesting that No. 3A short lumber could be used as well as 

 No. IC and No. 2C short lumber for furniture parts. 



Equations 18-35, 18-36, and 18-37 will predict square-foot yields of clear- 

 one-face cuttings from low-quality yellow-poplar bolts. Equations 18-38, 18- 

 39, and 18-40 give similar information for red maple. 



Yield tables based on the red maple equations are presented here as tables 27- 

 118 and 27-119. They give the maximum yields of clear-one-face, flat dimen- 

 sion from small low-quality trees and bolts removed in a stand improvement cut 

 of 18- to 44-year-old red maples in southern Illinois (Landt 1974). The dimen- 

 sion recovery factor (described by equation 18-39) ranged from 2.70 for trees 10 

 feet high and 6 inches dbh to 4.67 for trees 60 feet high and 15 inches dbh. In this 

 study, the square-foot area of dimension was measured by diagramming various 

 size cuttings (1 to 6 inches wide, 12 to 72 inches long) on each flitch. Ripping to 

 a specific width and then crosscutting out the defects rather than cutting random 

 width and lengths would reduce the yield. 



Yields of clear-one-face cuttings from oak, sweetgum, and yellow-poplar 

 bolts (table 18-64) increased with increasing bolt diameter and with increasing 

 number of clear faces on the bolt (bolt grade). Rift-sawing yielded significantly 

 more cuttings than a modified live-sawing technique. 



