SOFTWOOD GRADES
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lthough cabinetmakers generally prefer hardwoods, many fine pieces of furniture have been built with softwood. There are good reasons for using hardwood’s less expensive cousin: Softwood is generally more readily available than hardwood, and is easy to work.
Pine is one of the most popular choices of cabinetmakers. Its varieties include Eastern white pine, Southern yellow pine and species from the West, such as sugar pine, Idaho white pine and ponderosa pine. Douglas-fir, another Western softwood, is also gaining popularity as a cabinet wood. Sitka spruce and Western larch are two other good choices.
For cabinetmaking, you should restrict yourself to grades of softwood shown in the chart on the following page. Remember that softwoods are generally sold S4S—that is, planed smooth on both faces and jointed on the edges. And they are graded based on the board’s best face after surfacing.
Unlike hardwoods, softwoods are graded differently depending on the species; the grade for a California redwood board, for example, does not apply to a piece of ponderosa pine. You can obtain information about softwood
grading standards from the American Lumber Standards Committee in Germantown, Maryland.
Softwood grading takes both strength and appearance into account. Three grade categories—Select, Finish and Common—are often used for woodworking. Select and Finish grades must
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This French-Canadian nightstand was built entirely with pine—an attractive alternative to more expensive hardwoods. |
be clear of defects, while boards in the Common grades may contain defects such as tight knots. Select and Finish stock are seasoned to a moisture content of 15 percent or less. Common boards, used mainly in construction and homebuilding, may have up to a 19 percent moisture level. The quality of Common grade boards is further divided into categories 1 to 5, with the highest number corresponding to the lowest grade.
Some boards display a grade stamp, like the one shown on page 49. The stamp displays information about the species, moisture content when surfaced and grade of the stock. To avoid marring their appearance, however, 1-inch - thick boards in the better grades are often not stamped after surfacing. The stamp may also be missing from lesser grade boards that have been cut into shorter lengths by retail lumber dealers.
Keep in mind that softwood is sold according to nominal size, or green dimensions, which is different from a board’s actual size. A 2-by-4, for example, actually measures U/2 by ЗУ2 inches. The chart below shows nominal sizes of some commonly available boards along with their true sizes when surfaced.
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NOMINAL AND ACTUAL SOFTWOOD LUMBER SIZES
SOFTWOOD LUMBER GRADES FOR CABINETMAKING
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GRADES |
CHARACTERISTICS |
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Select В and BTR (supreme) |
Clear appearance and highest quality; minor defects and blemishes. Ideal with clear finishes. Not always available; expensive |
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C Select (choice) |
High quality; small defects and blemishes |
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D Select (quality) |
Good quality; defects and blemishes more pronounced |
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Superior Finish |
Highest quality of finish grade lumber; minor defects and blemishes |
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Prime Finish |
High quality with few defects and blemishes |
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No. 1 Common (colonial) |
Has limited availability and size ranges; may have small tight knots, making this grade appropriate if a knotty appearance is desired |
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No. 2 Common (sterling) |
Larger, coarser defects and blemishes; often used where a knotty appearance with strong character is desired |
DECIPHERING A GRADE STAMP
Most softwood grade stamps, like the one shown at left, contain five basic elements. A code number identifies the mill that produced the board, and the grade of the wood appears next to the trademark of the agency that established the rules for grading the wood (in this case, the Northeastern Lumber Manufacturers Association). The species is also noted; sometimes more than one species is stamped on the board, indicating it may be any of those listed. Finally, the seasoning information reflects the moisture content of the wood at the time it was surfaced: S-DRY means that the board was surfaced after seasoning and has no more than 19 percent moisture content; MC 15 refers to a board with a maximum moisture content of 15 percent; S-GRN is reserved for unseasoned wood surfaced with a moisture content above 19 percent. A board that has been surfaced while still green tends to shrink and its dimensions will not be as accurate as those of a board that has been surfaced after it was seasoned.
