Visual Grading
NDS Supplement table 4A
US Grading Agencies
- Redwood Inspection Service (RIS), a division of the California Redwood Association (CRA)
- Northeastern Lumber Manufacturers Association (NELMA)
- Northern Hardwood and Pine Manufacturers Association (NHPMA)
- Southern Pine Inspection Bureau (SPIB)
- West Coast Lumber Inspection Bureau (WCLB)
- Western Wood Products Association (WWPA)
Grade Stamps
When lumber of the same species and size is still at the mill, it is designated and separated by grade. It is then identified by a stamp and often inventoried by its grade and species. Different lumberyards sometimes use different names for the same grade. Grade designations depend on particular defects such as knots or wane. Grade does not indicate consistency of color or grain patterns.
Manufacturer: Mill's number, name, or symbol. (e.g. 12)
Certification mark: Symbol of agency providing quality-control supervision. (e.g. WWP®)
Grade: Often abbreviated. 1 Common shown. (e.g. 1COM)
Moisture content: Abbreviation for MC when board was surfaced. MC 15 is 15% or less;
KD or S-DRY is 19% or less; S-GRN is green wood with more than 19% MC. (e.g. S-DRY)Species mark: Symbol or abbreviation for types of tree. Example shown is Ponderosa pine. (e.g. PP)
Machine Stress Rated (MSR) Lumber
NDS Supplement table 4C
Machine Evaluated Lumber (MEL)
x-ray for density
NDS Supplement table 4C