Analysis of American hardwood board classification standards
□ Level 1 (1com) Grade 1 is suitable for the production of standard sizes of American cabinets, so it is often referred to as cabinet level in the United States. It is also for this reason that Grade 1 wood is widely used in the production of furniture parts. The minimum size of the first grade is 3 inches wide and 4 feet long, and the net aspect ratio is 66.67% (ths) to the minimum of the FAS level of 83.33% (not up to the FAS level). The minimum net footprint is 3 inches wide by 3 feet long and 4 inches wide by 2 feet long. The number of net faces depends on the size of the sheet. Both sides of the board must meet the minimum requirements of Grade 1. □ FAS level The original meaning of the FAS grade is derived from the original [first-class and second-class] grades, which refers to wood that can provide a longer net finish. This grade of wood is best suited for high-end furniture, interior joinery and solid wood lines. The minimum dimension of the panel is greater than or equal to 6 inches in width and greater than or equal to 8 feet in length. The FAS grade includes a series of sheets with a net-faced yield (accounting for the entire outer surface area) of 83.33% (10/12 ths) to 100%. The minimum size of the net plan should be 3 inches wide, 7 feet long or 4 inches wide and 5 feet long. The number of net finishes in a sheet varies depending on the sheet size, and the maximum number of sheets allowed is 1 to 2. The minimum standard for sheet length and width will vary depending on the type of material and whether it has been treated by kiln drying. Both surfaces of the sheet are required to meet the minimum requirements of the FAS rating. □ Pu 2A (2com) Grade 2 is often classified as economic grade, because the price and suitability of this grade of wood can make it a material for a wider variety of furniture components. This grade of wood is also a frequently used material for American hardwood flooring. The smallest board size in the 2nd grade is 3 inches wide and 4 feet long. The ratio of the net draw rate is 50% (6/12 ths) to 66.67% of the general grade 1 (not up to the grade 1). ). The minimum allowable net face size is 3 inches wide and 2 feet long, depending on the size of the board. If the worst face meets the minimum requirements of the 2A level, the level to which the better face belongs is irrelevant. □ Standard thickness of rough sawn timber The standard thickness of rough sawn timber is expressed in quarters of an inch. For example: 1 inch = 4/4 inch. Most American hardwood sheet saws are between 1 inch and 2 inches thick, although there are other thickness specifications, but the number is limited. The following are standard thickness specifications and corresponding metric sizes: 3/4 (3/4" = 19.0mm) 6/4 (1 1/2" = 38.1mm) 4/4 (1" = 25.4mm) 8/4 (2" = 50.8mm) 5/4 (1 1/4" = 31.8mm) 10/4 (2" = 63.5mm) □ Board ruler The ruler (BF) is the basic unit for measuring hardwood boards. One ruler unit is 1 foot (length) x 1 foot (width) x 1 inch (thickness). (1 foot = 0.305 meters, 1 inch = 25.4 mm) The formula for measuring the plate ruler is: [width (inches) x length (feet) x thickness (inches)] ÷ 12 The proportion of the net facet in each grade is measured in this 12-digit unit of measure. □ Thousand feet As the name implies, it is a thousand-foot ruler (BF), the English abbreviation is MBF, 1MBF=2.36M3 Note: The NHLA grading rules used in the US hardwood industry are based on imperial (inches and feet) units. But most export markets are more familiar with the metric system. In addition, the grading rules do not specify the width and length of the board. Bearing Ball,Self Aligning Ball Bearing,Steel Ball Bearings,Self Aligning Bearing Dongyang City Shuangchi Bearing Co.,Ltd , https://www.zjscbearing.com