Well-known, portland is the revolutionary base area of association of material of American needle leaf, having here provide most representative western orgnaization of authority of needle leaf material, all these orgnaizations are Committee on Standard of lumber of United States of Department of Commerce of classics United States (the grade orgnaization that ALSC) approbates. WWPA and WCLIB are the orgnaization that via approbating authority establishs a standard, such orgnaization is in the United States only 6. Visit times feeling is honoured can visit its orgnaization, learn classify knowledge.
Kind of lumber is cultivated to be able to process product of hundreds of kinds of wood western, press specific lumber grade sale. These grade are the standard that establishs gradually inside close centenary time, in order to consults specific lumber, make an orgnaization provide standard of appraisal of quality of a lumber to user, forestry centre and norms.
Divide roughly by final utility for: Structural level, press in building frame and construction to build bearing and laden function classification, cultivate kind of classification to conduce to simplify design program; Exterior grade, comment on graded especially according to the exterior of lumber, do not have the section scar, lumber that does not have feature and blemish completely to be judged to be the superlative degree;