As you begin to understand why downgrading makes sense for Walnut lumber, hopefully you’ll agree with us that it’s a good idea. But even if you don’t, it’s not likely to change anytime soon, so you’ll do well to understand precisely what the differences are between how Walnut is graded and how other North American hardwood lumber species are graded. The standards created by the National Hardwood Lumber Association (or NHLA) are a little complicated, using both size and percentage of clear-cuttings.
Category 1: First and Seconds (FAS)
Typically, FAS lumber is defined as being 83.3% free from defects on both faces, with a minimum board size of 6 inches wide by 8 feet long. FAS lumber must also include a minimum clear cutting size of either 3 inches by 7 feet or 4 inches by 5 feet. For Walnut, the main variations from the typical standards for FAS is that the minimum board size is 5 inches wide by 6 feet long and 80% must be 8 feet or longer. The clear cutting size is slightly smaller, too, at 4 inches by 3 feet or 3 inches by 6 feet. (Also unlike typical FAS lumber, FAS Walnut can include more defects: for boards 6-7 feet long and at least 5 inches wide, splits up to 6 inches on one end, wane along the edges, and a single defect are allowed, and for boards 8 inches wide or wider, 2 defects are allowed.
Category 2: Selects
In the Selects categories, the requirements are quite similar to those of FAS; the main distinction is that only one face must meet the requirements. For most species, one face must be 83.3% clear, with the other face meeting the requirements for #2 Common grade. The minimum board size is 4 inches by 6 feet, and the minimum clear cutting size is identical as for FAS, but for only one face. For Walnut, the only difference is that the minimum clear cutting size is 4 inches by 3 feet or 3 inches by 6 feet.
Category 3: #1 Common
Since the Common grades are, ironically, less commonly sought after, we’ll just look at the requirements for #1 Common grade lumber. Typically, lumber needs to be 66.6% clear on both faces, with a minimum board size of 3 inches by 4 feet and a minimum clear cutting size of either 3 inches by 3 feet or 4 inches by 2 feet. For Walnut, there’s just one change: the minimum clear cutting size is 3 inches by 2 feet. As you probably realize, the reduction in cutting size means that smaller boards are allowed into the grade; however, since the percentages of clarity remain the same, that’s really the only difference.
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Since 1798, when Hugh McIlvain established a lumber business near Philadelphia, the J. Gibson McIlvain Company has become one of the largest U.S. importers of exotic woods. As an active supporter of sustainable lumber practices, the J. Gibson McIlvain Company has provided fine lumber for notable projects throughout the world. Contact a representative at J. Gibson McIlvain today by calling (800) 638-9100.