Brooks Bros Guide to Timber Grading
The NHLA (National Hardwood Lumber Association) grades cover the majority of commercial hardwood species growing in the USA. The following is a brief summary of the grades, characteristics and defects of North American hardwoods.
The FAS grade, which derives from an original grade 'First and Seconds', will provide the user with long, clear cuttings - best suited for high quality furniture, interior joinery and solid wood mouldings.
Minimum board size is 6" and wider and 8' and longer.
The FAS grade includes a range of boards that yield from 83.33% (ten-twelfths) to 100% clear-wood cuttings over the entire surface of the board. The clear cuttings must be a minimum size of 3" wide by 7' long or 4" wide by 5' long.
The number of these cuttings permitted depends on the size of the board, with most boards permitting one to two. The minimum width and length will vary, depending on species and whether the board is green or kiln dried. Both faces of the board must meet minimum requirements for FAS.
FAS ONE FACE (F1F) (COMMON GRADE FOR THE UK MARKET)
This grade is nearly always shipped with FAS.
The better face must meet all FAS requirements while the poor face must meet all the requirements of the Number 1 Common grade, thus ensuring the buyer with at least one FAS face. Often export shipments are assembled with an 80-20 mix (80% being the percentage of FAS boards and 20% the percentage of F1F boards). These percentages are strictly left to the individual Buyer and Seller agreement. Note: Minimum yield 88.33% clear wood cuttings on the poor face of the board
Regional exceptions to the standard NHLA grades
Considered to be the elite of American hardwoods, Walnut is the favourite of the darker woods for fine furniture, interiors and gunstocks. Walnut grows in widely scattered stands throughout the eastern half of the United States. Historically the grading rules for FAS Walnut have been refined to encourage better use of the wood. Because of this, FAS Walnut grades allow for smaller boards, in both width and length. Natural characteristics are also admitted to a greater extent than the standard NHLA grade rules for other species. .
For a more detailed explanation and what Walnut grades and products are available contact your usual or nearest Brooks Bros Sawn Timber Sales Office.
The following photographs illustrate characteristics that occur in North American hardwoods. Some are inherent to certain species and others are generic to all. These characteristics either occur naturally in the timber or as a result of the drying process. The grades are based on the percentage of clear, defect free wood in the board.
The NHLA grading rules allow the following characteristics in clear cutting percentages for all grades and they are therefore NOT considered defects.
Note: Although the NHLA grading rules do not consider these characteristics as defects for the standard grades, allowances are made within the individual species.
For example, species such as Hard Maple and Ash are more desirable if there is a large portion of the board that is sapwood (white) and very little heartwood.
The reverse is true when specifying species such as Cherry, Oak and Walnut.
It is essential that the Buyers familiarise themselves not only with each species but the growing regions throughout the USA as well.
Climate, soil and growing conditions such as hills and valleys all play an important role in the growth of a tree.
As previously stated, the NHLA rules are the framework to starting the trading process. For further details on characteristics found in individual species please contact your usual or nearest Brooks Bros Sawn Timber Sales Office.
The NHLA grading rules do not allow the following characteristics in the clear cuttings for all grades and they therefore ARE considered defects.