Woods to Know: Black Walnut - Canadian Woodworking Magazine

Woods to Know: Black Walnut

Black Walnut (Juglans nigra)

by Peter MacSween, A&M Wood Specialty

Black walnut is one of North Americas finest cabinet woods, equally valuable as lumber or sliced into decorative  veneer. 

black-walnut
 
Forest grown walnut trees can exceed 100' in height with diameters up to 6'. However, since walnut has been actively harvested for at least the past 250 years, fewer examples of natural stands remain. Much of today's walnut grows on the fringes of farms and urban areas, so called doorstop trees. These trees tend to be shorter, branch earlier and exhibit faster growth. 
 
Walnut's ability to produce many different types of figured lumber and veneers is one of the traits that attracted early cabinet makers. It has also been very popular for  furniture, architectural woodwork, and decorative panels. Curly, stripped, burl, and stump figure are all present in walnut. Combined with  its inherent stability and easy workability, it's no wonder walnut has achieved the premium cabinet wood status it now claims. 
 
Walnut is a generally straight fine grained wood, occasionally with irregular grain that yields to all tools, hand and machines with ease. It must be dried slowly since it can be prone to casehardening. Once dried it is extremely stable and durable. 

black-walnut-endgrain
Black Walnut Endgrain
 
The heartwood ranges from a deep grey with purple overtones to a rich brown. Mature trees tend to produce an evenly coloured heart with faster growing trees exhibiting more variation in colour and pattern. The sapwood is a pale white, sharply demarcated from the heart. Most commercial lumber is steamed to even out the sap/heart transition. 
 
Walnut is extremely shock resistant, which makes it the first choice for rifle and gun stocks. Its ability to absorb recoil, without splintering is unsurpassed. The United States army maintained large inventories of walnut during both world wars for the manufacture of rifle stocks. 
 
Walnut is also an excellent wood for turning. Its natural oiliness allows the wood to slice cleanly. As well, iIts diverse figuring offers the lathe artist interesting design possibilities. It sands and polishes well, producing a rich, lustrous finish. Walnut is well suited for natural finishes.

black-walnut-turned-s

Woodworkers should be aware that walnut is graded differently from other hardwoods. Grade for grade, walnut quality is lower. One should expect smaller cutting lengths and more knots. This difference in grading is indicative of walnut's move from the forest to the "doorstop," with these trees producing lower quality material. 
 
Walnut may not be the dominant specie it once was, but it is still available in sufficiant quantities at a higher price. Walnut will always entice the woodworker with its workability and subtle beauty.
 

Facts To Know


Average Dried Weight41 lbs/ft3A measure of its weight at 12% moisture and an ambient temperature of 70°F.
Specific Gravity.66A measure of the ratio of its density compared to water (at 12% MC).
ShrinkageRadial: 5.5%,
Tangential: 7.8%,
Volumetric: 12.8%
Radial (the amount of crosswise shrinkage);
Tangential (the amount of lengthwise shrinkage);
Volumetric (the total amount of shrinkage.)
T/R Ratio1.4A measure of the uniformity of tangential to radial shrinkage.
Janka Hardness1010 lbfA measure of resistance to denting and abrasion.
Crushing Strength7,580 lbf/in2A measure of compression strength parallel to the grain.
ColourHeartwood: a light pale brown to a dark chocolate brown with darker brown streaks, sometimes with a grey, purple, or reddish cast. Sapwood: pale yellow-gray to nearly white.
GrainStraight grain,though sometimes irregular. Figured grain patterns such as curl, crotch, and burl are also seen.
TextureMedium texture and moderate natural luster.
WorkabilityVery easy
UsesFurniture, cabinetry, millwork, turning
Price$9.50/BF (8/8 stock)Approximate Pricing
 
  
Photos and Specifications Courtesy of: The Wood Database