SELLINGLUMBER 467 



equivalent on two or more corners on not to exceed ten per cent 

 of the pieces, shall be admitted. 



SELECT STRUCTURAL MATERIAL. 



(A rule incorporating suggestions by the United States Forest 

 Service. ) 



REQUIREMENTS FOR DENSITY AND RATE OF 

 GROWTH 



1. Shall contain only sound wood and be well manufac- 

 tured. 



2. Shall conform to the definition of Dense Southern Pine 

 as adopted by the American Society for Testing Materials, 

 August 21st, 1915, shown on page 463. 



For the purpose of determining whether any given piece 

 meets the requirements for density and rate of growth, the fol- 

 lowing rule, suggested by the United States Forest Service, 

 shall be applied. It will be sufficient if either end passes the 

 inspection. 



(1) Pith Present or Accurately Located 



(A) Radial line of 5" present. 



(a) Apply inspection over third, fourth and fifth 

 inches. 



(B) Radial line of 5" not present. 



(a) Apply inspection to the second inch on 2x3, 

 2x4, 2x6, 3x3, 3 x 4, 4 x 4, or any other dimen- 

 sion material that has less than 16 square inches 

 on the cross section. 



(b) In the larger material apply inspection to the 3 

 inches farthest from the pith. 



(2) Pith Not Present or Cannot be Accurately Located. 



(A) Material over 3" thick apply inspection to three inches 

 nearest the pith. 



(B) Dimension material 3" or less in thickness apply in- 

 spection to second inch of the piece nearest the pith. 



(3) The Radial Line Chosen Shall Show a Representative 

 Number of Annual Rings of Growth and Per Cent of 

 Summer Wood. 



Restrictions on Knots in Beams. 



3. Shall not have in Volume 1 sound knots greater in diam- 

 eter than one-fourth the width of the face on which they appear 



