2682 Chapter 22 



Table 22-25 — Minimum standards for roundwood suitable for manufacture of sawn 

 timbers and round or split props (Timson 1978b) 



Product, mill equipment, and specifications 



Sawn products, standard sawmill 



Minimum diameter: 7 inches at the small end 



Minimum length: 6 feet 



Sweep (fig. 22-62): Not to exceed one-half the diameter of the small end, and allowed only in 



sound pieces without large knots ^-^ 

 Decay or hollowness: Pieces up to an including 10 inches diameter, none. Pieces 1 1 inches to 15 



inches in diameter, one-fourth diameter. Pieces over 15 inches, one-half diameter. 

 Surface defects: No surface defects larger than width of one face.^ 

 Straight seams allowed, but spiral seams limited to one face. 

 Sawn products, bolter mill 



Minimum diameter: 6 inches at the small end 

 Minimum length: IVi feet 

 Decay or hollowness: None 

 Sweep: None 



Surface defects: None larger than width of one face 

 Sawn products, special 



Minimum diameter: 12 inches at small end 

 Minimum length: 18 inches 

 Decay or hollowness: None 



Surface defects: None larger than width of one face 

 Maximum defect: One large defect per piece 

 Round props 



Minimum size: 4'/2 inches in diameter at small end, and 4-'/2 feet long. Over 4-'/2 feet long, 1 



inch diameter for each foot of length.^ Some props shorter than 4-'/2 feet are sold, but they 



must be at least 4-'/2 inches in diameter. 

 Sweep or crook: Slight. 

 Decay or hollowness: None. 

 Maximum knot size: No greater than width of one face and cannot interfere with strength (in 



compression parallel to grain). 

 Split props 



Some specifications as round props. 



End measurement on props with one split surface: Measure between bark and split surface 



perpendicular to split surface; distance in inches must equal prop length in feet (see fig. 22- 



62). Minimum, 4-V2 inches. 

 End measurement on props with two or more split surfaces: Measure along split surfaces (bark 



portion considered a split surface — see fig. 22-62). Each of two surfaces measured in inches 



must equal prop length in feet. Minimum, 4-'/2 inches. 



'a large knot has a diameter greater than one-half width of one face. 



^A log face is one-fourth the circumference along the surface of roundwood. 



■^The Federal Mine Safety Law allows no less than 1-inch diameter for each 15 inches of length 

 with a minimum diameter of 4 inches. The minimum standards in this table are based on 1978 

 practices. 



OTHER TIMBERS 



Hardwood timbers of various dimensions are commonly used around con- 

 struction sites in the South and East. Pieces may be as small as 4 by 4 inches and 

 4 feet in length for temporary support of pipe lines during laying operations, or 



