Provides a simplified explanation of the NHLA grading system, which is the national standard for the US hardwood lumber industry and forms the basis for export grading. Bob Sabistina, Consultant to AHEC for Lumber Grading, talks an audience of lumber salesman through the NHLA Grading Rules, covering measurement, grades, defects and species. Today, NHLA grading rules are not only the dominant grading system for hardwood lumber in the United States, but also form the basis for much of the international trade in hardwoods. Most hardwood lumber produced in this country is graded using the rules developed and maintained by the National Hardwood Lumber Association (NHLA). What do the lumber grades FAS and Common really mean to you when buying the hardwoods for your next project. For more than a century, the hardwood lumber industry has held to a central grading standard established by the National Hardwood Lumber Association (NHLA). Change of Species Changes the Rules.
In the United States, standards for grading hardwood are set by the National Hardwood Lumber Assn. The standards are voluminous, replete with exceptions, special rules for certain species, and many details. Here we will only try to illustrate the principles behind the grading, with a few indications of how the home woodworker can use them. The following rules are used for determining hardwood grades and generally correspond to the percentage of usable lumber in a given board of rough lumber. Due to numerous variables, exceptions, and special grading rules applicable to certain species, the official rules of the National Hardwood Lumber Association (NHLA) should be referenced. U.S. hardwood lumber is graded according to the rules of the National Hardwood Lumber Association (NHLA). 3Z Hardwood strictly adheres to these rules. Below are resources for hardwood lumber grading rules. NHLA Grading Rules For North American Hardwoods (downloadable pdf ).
U.S. Hardwood Grading Rules (16 pages) Measurement, FAS and FAS/1F Grades, No. Ash, Cherry, Cottonwood, Gum, Hard Maple, Soft Maple, Red Oak, White Oak, Tulipwood, Walnut, and Summary of U.S. Hardwood Lumber Grades. Lumber Grades. You can use accepted industry standards and grading systems to describe the look you and your customer want, and the best way to achieve it within the budget. Hardwood lumber grades and grading rules have been established and are governed by the National Hardwood Lumber Association (NHLA). The NHLA grades are based on the percentage of clear-defect free wood on a board. The measurements of this percentage are referred to as clear-cuttings. Other than the FAS grades, the grade of the board is determined from the percentage of these clear cuttings and do not consider defects outside of the clear areas.
Sawn Wood Grading
Occasional clusters of tiny pin knots, or very small, dark streaks of gum set Cherry apart from any other hardwood. Both of these natural characteristics found in Cherry are permitted under the NHLA grading rules for this species, and result in individual pieces which are truly unique.