From the archives

Buying Hardwoods:
Understanding Industry Grading, Cuts and Measurements

No matter how long we've been working with wood, the material still manages to surprise us every now and then. Wood is unusual in that most of the surprises are quite pleasant. There's nothing like the feeling of applying a first coat of sealer or finish and watching a project literally come to life right before your eyes. While that reward comes at the end of the construction process, it is in large part due to decisions you made before a single cut was made. I'm talking, of course, of the buying process.

The easiest way to examine that process is to separate the individual decisions that need to be made. These include:

1. Choosing a Species
2. Choosing a Cut
3. Choosing a Grade
4. Choosing how much lumber to buy, and in what dimensions
5. Choosing a Supplier

Links to Relevant Hardwood Sites

1. Choosing a Species
Hardwoods are deciduous (non-evergreen) trees which produce broad leaves, a fruit or a nut, and in most cases go dormant in the winter. The term "hardwood" isn't literal: some species of softwood, like old growth fir, are pretty dense, while some of the trees classified as hardwoods (like aspen) are really quite soft. The factors which control our choice of species are aesthetic concerns (color and grain patterns), durability, and workability. While the aesthetic factors are essentially subjective (everybody has to make their own call), durability and workability are far more predictable. They can both be measured, as both depend quite a bit on density and hardness.

Hardness
The hardest domestic species, according to the USDA, are (in order, hardest first) hickory, pecan, hard maple, white oak, beech, red oak, yellow birch, green ash, black walnut, soft maple, cherry, hackberry, gum, elm, sycamore, alder, yellow poplar, cottonwood, basswood and aspen. Many imports such as rosewoods and ebony are at the top of the hardness scale, while mahogany, sapele, makore and other popular architectural millwork species are somewhere between the middle and the lower end of the scale. Hardness doesn't necessarily mean hardship: just because a species is hard, it isn't always hard to work. For example, I'd much rather work any of the oaks than gum or cottonwood. Oak is predictable and reliable.

Density and hardness can be challenging to grasp.I personally like simple definitions, such as "Wood density is weight per cubic foot." That gem originally came from the Wieland & Sons Lumber Co. site, which went on to say that "density is a way of determining the ease of working a specific species of wood. Dense woods are harder to work with and fasten together, but once fastened they hold much better than less dense types of wood." The Wieland site includes a table (below), which lists the densities of various domestic hardwoods. The numbers are all approximate and "should only be used for relative comparisons among each other". What's interesting is that the density certainly has a strong relationship to the hardness of the stock (basswood goes through the table saw with a lot less effort than hickory), but I'm not so sure that I totally agree with the statement that density is a way of determining the ease of working a specific species of wood. For example, butternut is relatively soft (lower density), yet it can be a pain to sand and finish. That's because it is, in the words of my pre-teen son, " kind of furry". One other point worth noting is that pine, a softwood, can actually have a higher density than basswood, which is categorized as a hardwood. (The USDA list is in a slightly different order, which probably reflects the subjective nature of wood.)

HICKORY 0.72
WHITE OAK 0.68
RED OAK 0.63
HARD MAPLE 0.60
ASH 0.56
WALNUT 0.55
HACKBERRY 0.53
RED ELM 0.53
CHERRY 0.50
GREY ELM 0.50
SOFT MAPLE 0.48
ASPEN 0.38
PINE 0.38
BASSWOOD 0.37

Grain Pattern and Defects
Grain pattern is important, and is an indication of how well a piece of wood will work, and how stable it will be over the years. Straight grains (such as those found in quartersawn stock: see below) present a workpiece which will in general move less and hold more: it will be stronger than stock with wavy or spiral grain, although it might not be nearly as interesting aesthetically. Irregular grains such as fiddleback or bird's-eye are beautiful to look at, and rather difficult to work. The key is perhaps to progress from straight grain to figured stock at the same rate that your woodworking skills evolve.
Some species are prized for their natural defects (such as burls, insect damage, water damage and so on). But nobody buys lumber for its manmade defects. These are generally related to the drying process.

More Information on Specific Species
For more information on a specific species, there are a number of apps on the market. One can also visit The American Hardwood Information Center and at the top of the page click on 'Species Guide'. Another wonderful resource is no longer in print, but is well worth searching for online. It's Ernest Scott's beautifully produced book, The Illustrated Encyclopedia of Working In Wood (ISBN 185152875X 9781851528752). The glossary defines hardwood as "a botanical term used for broad-leafed trees. The wood is not necessarily hard."

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2. Choosing a Cut
There are essentially three ways to saw a log and each one produces a very different kind of board. The three methods are Plain sawn, Quartersawn and Rift Cut.
Plain sawn stock (on the left, below) is by far the most economical and, therefore, the most common cut. This produces the familiar cathedral grain found in standard #2 softwood boards at a lumberyard. It involves the least amount of waste and the most lumber from each log.
Quartersawn hardwood (center in the illustration below) is produced when the log is cut radially at a 90-degree angle to the growth rings. This produces boards with very straight, tight grain and it's absolutely ideal for furniture building. Gustav Stickley, perhaps the greatest woodworker America has ever seen, used quartersawn white oak almost exclusively for his Mission and Arts & Crafts furniture. The cut is not very economical, so the price of the stock is considerably higher. Rays or flake, which show up as golden ribbons crossing the grain in oak, are a prized attribute of quartersawn lumber.
Rift cuts (at right in the illustration) are a variation on quartersawing, where the cut is made at a 30-degree or greater angle to the direction of the growth rings. This produces a very clean, uniform grain pattern which is ideal when boards are to be edge-glued to make panels: the joints are almost invisible. This cut is rare and quite pricey, and is used in top-end architectural millwork shops - the kinds of shops that produce fancy desks and paneling for the boardrooms of the Fortune 500 companies.

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3. Choosing a Grade
When ordering hardwood either over the Internet or over the counter at your local lumberyard, the National Hardwood Lumber Association guidelines for hardwood grading (below) are a great place to start. But they are not the only consideration. By its nature, wood is not all identical. The Association's rules get you close, but you'll still need to add some specs of your own when placing orders. For example, if you just ask for FAS cherry, you will get a mix of heart and sapwood in random widths. If you need all heart in 7" boards, you need to tell your salesperson.
The following grades cover almost every hardwood board that is suitable for hobbyists who turn on the lathe or build furniture. They are...

FAS Firsts & Seconds - the clearest grade, 10/12ths of each side of every board is clear.
FAS is generally used for large clear parts such as moldings, tabletops, solid wood doors etc.
FAS-1 Firsts & Seconds on one face - 10/12ths of each board is clear on one side.
It may have minor defects on the other.
#1 No. 1 Common is 8/12ths clear and is a cabinet grade hardwood.
More than 50% of #1 hardwoods end up in kitchen cabinets.
#2

No. 2A Common is 6/12 clear and most of it ends up as flooring.
No. 2B - 6/12 sound wood, it is essentially used in upholstered furniture.

The NHLA site is worth a visit (just click on their name in the hyperlink above). They have a very comprehensive array of publications covering a multitude of hardwood topics, and their prices seem quite reasonable.

For those of you selling hardwoods or hardwood products professionally, or for serious amateurs who want to know more, there's a very detailed analysis of industry standards available on the Web. It covers everything from humidity to defects. You can download this information as a PDF file from the Architectural Millwork Institute, a most reputable and impressive organization. The file is an extract from their manual "Architectural Woodwork Quality Standards Illustrated", which they sell for $10.00 to members and $100.00 to non-members. The book can be ordered online or by phone: (301) 953-7264. (Woodezine has no connection with the Institute. We just admire what they do.)

If you haven't downloaded a PDF document before, you might need to go to the Adobe site to put Acrobat Reader™ on your computer. And I should mention that it will look like nothing is happening for several minutes while the AWI file downloads. Just hang in there.

Finally, a word about kiln and air drying. We had intended including information on this subject in this feature, but we gathered so much information that we've decided to do a complete article on it in the March issue instead. For now, let's just say that we prefer kilns to air drying, and we always ask our supplier to deliver kiln-dried lumber. I'm sure some of you disagree.

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4. Choosing how much lumber to buy, and in what dimensions
Hardwoods are sold by the board foot, which is 144 cubic inches (for example, 1" x 12" x 12" or perhaps 2" x 6" x 12") in its rough state. Generally speaking, the thicker or longer the board is, the higher the price it will command per board foot. Species, cut and grade all factor into the price. The most common thicknesses for hardwood are 4/4 (called "four quarter"), which is 1" thick in its rough state; 5/4 (1-1/4" thick), 6/4 (1-1/2" thick) and 8/4 (2" thick). A myriad other thickness are available, especially if you buy a log and have it milled to your custom specs.
If you have access to a thickness planer and a substantial band saw which is capable of resawing wide boards, your best bet is to buy the thickest stock you can. This is especially true for turners who are going to face-glue boards to create large turning blanks, or furniture builders who make laminated curved pieces. If you're building fairly conventional projects, you may want to save a few dollars and stick with 4/4 stock.
While most yards sell hardwood lumber unplaned (rough), some companies sell only S2S stock. This is planed on two faces, but the edges are not straight. You can usually have the company rip one edge straight. Planed stock usually comes in at 13/16" thick, which is wonderful if you're edge-gluing boards and want to plane them to 3/4" after the glue cures.
The most expensive way to buy hardwood is planed on all four sides, and it's probably not as useful either. The boards have been ripped to a uniform width, so the mill may have taken 1/16" off at one end of the board, but maybe and inch or two off the other end.

SHOP TIP:
When you bring lumber home, let it sit for a few weeks if possible, to acclimate to the ambient humidity in your shop. This will reduce the amount of movement after your project has been assembled.

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6. Choosing a Supplier
There's no question that nothing beats a hands-on visit to the hardwood supplier, where you can examine each and every board at your leisure and pick the cream of the crop. However, that's not really a possibility for millions of woodworkers who live outside major cities (myself included!). The next best option is to hook up with the biggest cabinet shop in town and talk them into letting you raid their stash every now and then. Other options include hooking up the trailer, loading a couple of buddies from the local guild, and then driving half a day to the nearest mill to buy air-dried stock which you can share. If you live anywhere along the east slope of the Rockies, call Rattlesnake Woods in Cheyenne, Wyoming at 307-214-4328. Shipping costs can be quite reasonable from online suppliers too: here are a few to get you started...

L.L. Johnson Lumber Mfg. Co. Charlotte, Michigan
Woods Unlimited San Leandro, California
World Timber Corp, Inc. Hubert, North Carolina
Rockler Companies Locations nationwide
Talarico Hardwoods Mohnton, Pennsylvania
Steve Wall Lumber Co. Mayodan, North Carolina
Hibdon Hardwood St. Louis, Missouri
Goby Walnut Products Albany, Oregon
Exotic Woods Co., Inc. Sicklerville, New Jersey
Goosebay, Inc. Chichester, New Hampshire


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For more information on hardwoods, visit these excellent Web sites...

The Hardwood Council

The Architectural Millwork Institute (AWI)

Wieland & Sons Lumber Co

American International Forest Products

National Hardwood Lumber Association

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