Search results
The National Grading Rule establishes the lumber classifica-tions and grade names for visually stress-graded dimension lumber (Table 6–2) and also provides for the grading of dimension lumber by a combination of machine and visual methods.
Hardwood lumber is usually graded on the basis of the size and number of cuttings (pieces) that can be obtained from a board when it is cut up and used in the manufacture of a hardwood product.
The SPIB Standard Grading Rules for Southern Pine Lumber provide for numerous visual and mechanical lumber grades. However, not all of those possible grade/size combinations are produced or used in the marketplace.
27 sie 2020 · AMERICAN WOOD COUNCIL Table 4A Reference Design Values for Visually Graded Dimension Lumber (2" - 4" thick)1,2,3 (All species except Southern Pine — see Table 4B) (Tabulated design values are for normal load duration and dry service conditions. See NDS 4.3 for a comprehensive description of design value adjustment factors.)
ASTM International consensus standards D245, D2555 and D1990 are all used to assign design values for bending, tension and compression parallel to grain to visually graded lumber. The standard used is dependent upon the species or species grouping under consideration and the size of the member.
All boards are graded from the better face. There are four Eastern White Pine Common grades: Finish, Premium, Standard and Industrial. The grades of Finish and Premium may be grouped together as Premium & Btr. All thicknesses. Widths — 3” and wider. Lengths — 6’ to Skip — Hit and miss on reverse face or light skip on 16’.
On January 30, 2013, the Board of Review of the American Lumber Standard Committee approved new design values for Southern Pine dimension lumber of all sizes and grades to be effective June 1, 2013. These design values for selected lumber sizes are tab-ulated in this publication.
