456 APPENDIX A 



lumber to a grade intended for a given use, when it possesses defects which unfit it 

 for this use, destroys the basis of sound business. • 



Again, a grade, as applied to the lumber of a given species or region, must be so 

 defined as to permit of securing a sufficient volume of output qualifying for the 

 grade to make it a commercial or market product. No purpose is served in making 

 grades for clear lumber, to apply to second-growth stands which produce little if any 

 lumber of this grade. 



Defects characteristic of one species but absent or rare in others call for modi- 

 fications of grading rules to suit the species in order, to prevent the rejection of too 

 large a percentage of the output for grades for which it is otherwise suited. 



To secure uniformity in both definition and application, grades of lumber are 

 established by regional associations of lumber manufacturers and dealers, which 

 frequently employ a corps of grading inspectors acting under a central head. These 

 grading rules are modified from time to time as market conditions change. The 

 latest specifications for any region or species should be obtained from the local 

 associations. Not only do specifications change, but there is considerable fluctua- 

 tion in their application as a whole, and in individual mills, which it is the purpose 

 of inspection and standardization to avoid as far as possible. 



354. Grades for Remanufactured and Finished versus Rough Lumber. For 

 the purpose of valuing logs and standing timber, only those grades of lumber are 

 serviceable which can be applied with some degree of accuracy directly to the log. 

 Lumber is finally sold on the basis of its grade when finished or remanufactured. 

 But these final grades are made the basis of the grading of the rough boards on the 

 sorting table, with the modification that the better grades of rough lumber may be 

 split up into several special grades, including lumber intended for specific uses. In 

 all such cases, the general grade of the rough lumber is the basis of log grading. 



Structural and dimension lumber calls for a different basis of grading, as do 

 sawed cross ties. Where a considerable proportion of the output is in these forms, 

 the basis of log grading is affected. While a system based on this form of products 

 could be worked out for logs, it has not been attempted, but the basis of log grades 

 has been confined to 1-inch rough lumber. The average value of each standard grade 

 of lumber may be obtained from that of the grades of remanufactured lumber which 

 it produces. 



It is always possible to recognize and estimate separately the quantity and value 

 of trees containing unusual or special dimensions, in the nature of piece products. 



356. General Factors which Serve to Distinguish Lumber Grades. Face. Lum- 

 ber is graded on the appearance of the poorest face for certain uses and in certain 

 regions. For other uses and in other regions, the appearance of the best face deter- 

 mines the grade. The specific practice is in each case determined by the local grad- 

 ing rules. 



Defects. With respect to perfect pieces, all departures from standard as defined 

 in § 352 constitute defects. With regard to each specific grade, the defects which 

 disqualify the piece and throw it into lower grade are defined. Defects which dis- 

 qualify in one grade may be accepted in the grade below. 



The principal defects are caused by, 



1. Knots, sound or unsound, encased, firm or loose, and knot holes. 



2. Rot. 



3. Shake, season checks, seams and cracks. 



4. Pitch. 



5. Worm holes. 



6. Stain, either as blue sap or red heart. 



