Don’t worry, there’s no actual test – but that doesn’t mean that lumber grades aren’t important.

From high grade to low grade, each aspect of the lumber and wood panel markets have their grading techniques, standards, and own grading systems… needless to say, it’s quite a bit of information. If you’re looking for a simplified guide to lumber grades in manufacturing, this is the article for you!

If you feel like ‘lumber grades’ seems like a broad term, then you’re 100% right. Lumber grades refer to the various grading systems throughout the lumber industry. Today, however, we’ll be breaking down the lumber industry into three distinct parts – softwood, hardwood, and panel products.

When grading softwoods, it’s important to understand that softwood lumber grades are set forth by the American Softwood Lumber Standard created by the U.S. Department of Commerce. The third-party body that grades softwoods based on these standards is known as the American Lumber Standard Committee. This not only has ramifications for American sawmills but North American sawmills more generally. All softwood lumber imported by other countries, namely Canada, must meet the requirements set by the American Softwood Lumber Standard.

With the guiding doctrine out of the way, let’s talk about how softwood lumber grades work.

Softwood lumber grades are given a numeric score from 1-4. If softwood is graded as no. 1, it’s typically the highest quality softwood you can buy – this lumber is free of defects and blemishes. On the opposite side of the scale, no. 4 lumber can have several defects, knots, and scratches.

No. 1 lumber is used to build furniture and other works that require aesthetically pleasing lumber. In whatever role it plays, it’s sure to be strong and blemish-free. No. 2 lumber is typically used as framing in construction. Although no. 2 is still fairly pleasing to look at, it’s allowed to have any quantity of knots as long as they are within the size and spacing requirements set by the American Softwood Lumber Standard. No. 3 and 4 lumber are used as utility lumber – this is the type of lumber manufacturers use. Although this wood may have many knots, it may not be perfectly straight, and it may not be pretty to look at, it’s some of the most commonly used lumber in the commercial market.

No. 3 and 4 lumber won’t be found at your neighborhood lumberyard but are commonly sent to manufacturers and remanufacturers to be sold and/or made into other industrial wood products. Examples of these products are pallets, crates, dunnage, wood blocking, and more!

There are other lumber grades for softwood as well, but they’re not really in the wheelhouse of manufacturers. These other lumber grades are based on stress grading and appearance.

Formal lumber grades for hardwood are set forth by the National Hardwood Lumber Association, an organization founded in the early 20^th century whose purpose is to facilitate the production and sales of hardwood across the United States.

Strap in because these lumber grades can be a little confusing!

Like softwoods, we’ll start at the top (the highest quality) and work our way to the bottom.

Up first is Firsts and Seconds (FAS), the premium hardwood used to create furniture. Next is FAS One Face, used where only one side of the wood needs to be visible. After that is Select grade, a replacement of a little less quality than FAS or FAS One Face. All three of these grades are considered desirable pieces of lumber used in homes, decoration, and more. These grades are highly valued.

In the middle of the pack comes No. 1 Common. This grade is used as a “shop” grade, being less expensive than the first three, but still good quality. After that is No. 2A and 2B Common, which can be used for panel products and other utility applications.

Finally, the last of the grades are 3A and 3B common, these are typically sold to manufacturers to be used for pallets, crates, and other industrial wood items.

A mouth full, right?

Fortunately, over the long history of the hardwood lumber industry, hardwood professionals and manufacturers have created a less formal and easier system to identify different grades of hardwood. Like several things in this industry, these lumber grades take a little bit of context to understand.

Throughout human history, people have used hardwoods for many different applications. They’re strong, dense, and slow-growing. Because of this, the patterns in the wood can be beautifully complex and unique – that’s why craftsmen have used hardwoods as flooring, crown molding, and furniture for centuries.

Although certain parts of hardwood trees are beautiful, other portions of the tree can be knotted and ugly and can’t be used for aesthetic purposes. This hardwood lumber becomes utility lumber… we call them cants.

Cants are described as “a log sawn on all four sides.” After they leave the hardwood mills, these cants simply look like squared logs. Although this is the traditional definition, many in the lumber industry like to think of cants as hardwood lumber that ‘cant’ be used for furniture. An easy way to remember, right?

Although it’s not as specific as other lumber grades, it has become an industry norm for lumber professionals to use cants as an acceptable term. Cants are sent to manufacturers to be used as dunnage, make pallet cut parts, and more. Many manufacturers prefer these hardwood cants because of their strength and durability.

Another form of hardwood lumber used in manufacturing is blocking. Hardwood blocking is cut from timbers of hardwood trees that are either too small for railroad ties or have too many defects to be graded for commercial use. Blocking is typically smaller than cants and is used as a form of strong dunnage across many industries.

Yes, they do! Much like softwoods and hardwoods, wood panel products have unique lumber grades as well. Although they’re not technically lumber, they are surely a lumber product and, in turn, have specific lumber grades. Let’s start with plywood, considering it’s the original wood panel product.

Unlike hardwoods, the lumber grades for plywood are very straightforward. The grades are literally elementary – A, B, C, and D. Much like the softwood lumber grades, the lumber grades for plywood go in descending order. A, being the highest quality without defects, and D, having the most flaws and defects.

At Conner, we use C and D grade plywood in the making of crates, as dunnage, and other uses. Despite defects, these pieces of plywood serve in the manufacturing industry very well.

Let’s move on to OSB.

OSB is much more like hardwoods as far as its lumber grades go. Although there are formal OSB grades, many in the manufacturing industry take a more casual approach when talking about OSB grades. This isn’t because of laziness or ignorance, but because each mill calls their OSB grades by different names – this is fairly common across the entirety of the lumber industry.

OSB is typically separated by the number of defects found after its production. Unlike lumber, OSB isn’t manufactured the same way every time. Some OSB is made to bear weight, whereas other OSB is made to withstand humid environments. Regardless of these different purposes, OSB mills still make ‘cuts’ from all of their OSB.

The lumber grades for OSB, although they differ from mill to mill, typically go from on-grade (consumer use) to industrial, and then to utility use. Utility use OSB is called by a variety of names, two of the most common terms are mill-select, mill-certified, or “shop”.

Manufacturers use industrial and mill-certified OSB to create siding for crates, tops of pallets, dunnage, and more.

Lumber grades may not be the most exciting aspect of the lumber industry, but they’re essential to understanding everything we do. Whether it’s softwood, hardwood, plywood, or OSB, we hope you now feel more knowledgeable about lumber grades across the industry.