BLACK WALNUT HARDWOOD IDENTIFICATION GUIDE

WALNUT HARDWOOD IDENTIFICATION GUIDE

An In-Depth Look at Walnut's Characteristics, Color, Grain & More

WALNUT

OTHER COMMON NAMES

Black Walnut is primarily referred to as Black Walnut or Walnut, but can also be referred to as American Walnut or eastern American Walnut. [1]

LATIN NAME

Walnut’s scientific name is Juglans nigra. [2]

CHARACTERISTICS - WALNUT

While there is diversity in walnut species around the world, walnut is the only dark wood native to North America. [6] For this reason, the species has high demand among woodworkers and craftsmen.

Walnut heartwood is known for having a distinct light brown to dark chocolate brown color, while also exhibiting gray, purple, or reddish hues. walnut sapwood is a creamy white to pale yellow color, creating a clear differentiation, and is more susceptible to discoloration over time. [2]

Authentic walnut has slight variations of coloring throughout. Both heartwood and sapwood from American walnut can be used in natural hardwood products, depending on preference or project, but the dark chocolate brown heartwood is most popular.


MAIN USES - WALNUT

Walnut is commonly chosen for its superior, classic look. The beauty of walnut has created high demand, which leads to pricing that is higher than other domestic hardwood lumber options.[6]

The natural coloration of walnut is extremely unique, so most pieces of walnut lumber are not stained or painted in order to preserve the wood’s inherent characteristics. Instead, the unstained wood is typically finished with a clear coat lacquer, wax or oil.[6]

Using a clear coat lacquer can provide some protection from the elements, but the natural color of walnut can be slightly altered from exposure to sunlight. [6] Regular application of proper oil will help keep walnut’s rich, dark brown colors intact.

Common applications for walnut lumber include solid hardwood flooring, fine furniture, live edge tables, cabinetry, doors, interior paneling, dowel rods, plywood, mouldings, trim, musical instruments, veneer and gunstocks. [3]

DOORS
FURNITURE
CABINETRY
DOWEL RODS
MOULDINGS & TRIM

MILLING

Walnut must be dried slower than many other species, but is dimensionally stable once dry. [3] Walnut shrinkage from green to 6% MC (moisture content) for flat sawn lumber is approximately 6% and overall volumetric shrinkage is close to 12%. [2]

North American Walnut boards tend to be more narrow and weigh about 38 pounds per cubic foot when the moisture content is at 12%. [2] Kiln-dried lumber weighs about 3 pounds per board foot, and walnut wood is rated moderately for its durability, bending, crushing, and steaming strengths.


HARDWOOD PROPERTIES - WALNUT

Black Walnut offers a level of workability that is compatible with power tools, woodworking by hand, or steam bending. [2] It is also known to be strong, durable and resistant to shock and decay. [7]

Many opt for quarter sawn North American Walnut that has a naturally straight grain, but other grain patterns are can be preferred (especially by woodworkers), depending on the application—burls, cathedral and crotch. [4] Burls create a swirling pattern, which is the highest prized part of the wood, and typically used for veneer and gunstocks. The cathedral pattern is created when the lumber is flat sawn, and crotch wood is a unique pattern that results in V-shaped flares where the tree has formed branches. [4]

When working with walnut, keep in mind that creating deep cuts along the grain may cause the wood to dismantle. It is recommended to cut shallow passes to eliminate any wood from popping out. [4] Grain variations range from very open to almost closed—open-grain walnut carves easier than closed-grain, which requires a finer finish.[4]

According to the Janka Hardness Scale, American Walnut wood is moderately hard, rating at 1,010lbf (pounds of force). [5]

Most adhesives perform well with American Walnut, but it's critical to remove all excess, as dry adhesives can discolor the wood. [2] Walnut responds well to nailing, polishing, and colored stains, but clear-coating is the preferred method, yielding an excellent finish.

Janka Hardness Scale


ENVIRONMENTAL PROFILE - WALNUT

Black Walnut trees flourish in deep, rich soils that are moist. The highest quality walnut trees are typically grown in the American midwest, between Ohio and Iowa. They also grow from Texas to Georgia and across the upper midwest and Great Lakes regions including Minnesota, Wisconsin, Michigan, and into southern Ontario, Canada. [1] The American Walnut tree reaches a height of 100-120 feet tall and ranges from 3 to 6 feet in diameter. Walnut trees typically grow a relatively tall, straight trunk with few branches near the ground. [2]

Walnut trees contain an acidic substance that is found throughout the roots, leaves, seed husks and bark that can be toxic to surrounding wildlife. Walnut trees can also become susceptible to pests and disease over time. [1]

Volume of live trees on forest land, 1000 m3

All data derives from Forest Inventory Data Online (FIDO), a component of the U.S. Forest Service Inventory and Analysis Program (FIA). Data was compiled by AHEC in January 2016 using the most recent state inventory available (2014 for most states). "Forest volume" refers to "net volume of live trees on forest land," as defined by FIA (see glossary). FIA forest volume data is available for 49 U.S. states (Hawaii and Washington D.C. are omitted) with total hardwood forest volume of 18.1 billion m3 of which 13.5 billion m3are commercially significant.


WALNUT PRODUCTS AT BAIRD BROTHERS

Baird Brothers Fine Hardwoods is happy to assist with any questions you have about our walnut products, which include a variety of Walnut doors, Walnut mouldings, Walnut S4S lumber, Walnut plywood and other items.

 

Please call 1-800-732-1697 or Contact Us if you need help with our extensive inventory.


COMPARISON TO OTHER WOOD SPECIES

Source: The Department of Agriculture's Wood Handbook

LumberSpecific GravityJanka HardnessModulus of Elasticity (MPa)Impact Bending (mm)Grain
African Mahogany --- 830 lb 9,700 --- Medium/Coarse
Alder 0.41 590 lb 9,500 510 Fine
Ash 0.6 1,320 lb 12,000 1,090 Fine
Basswood 0.37 410 lb 10,100 410 Fine
Beech 0.64 1,300 lb 11,900 1,040 Fine/Medium
Birch, Yellow 0.62 1,260 lb 13,900 1,400 Fine
Cedar, Western Red 0.32 350 lb 7,700 430 Fine
Cherry, Brazilian 0.91 2,350 lb 22,510 --- Medium
Cherry 0.5 950 lb 10,300 740 Fine
Cypress 0.51 510 lb 6,300 --- Medium
Douglas Fir 0.48 710 lb 12,300 660 Medium/Coarse
Hemlock 0.4 540 lb 8,300 530 Coarse
Hickory 0.66 1,820 lb 11,900 1,120 Medium
Maple, Hard 0.63 1,450 lb 12,600 990 Fine
Maple, Soft 0.47 700 lb 7,900 640 Fine
Oak, Red 0.63 1,290 lb 12,500 1,090 Coarse
Oak, White 0.68 1,360 lb 12,300 940 Coarse
Pine, Eastern White 0.35 380 lb 8,500 460 Medium
Pine, Ponderosa 0.4 460 lb 8,900 480 Medium
Pine, Yellow (Shortleaf) 0.51 690 lb 12,100 840 Fine/Medium
Poplar 0.42 540 lb 10,900 610 Medium
Sapele 0.67 1,410 lb 15,930 --- Fine
Teak 0.66 1,070 lb 10,700 --- Coarse
Walnut (Black) 0.55 1,010 lb 11,600 860 Medium

*Data is based on a moisture content of 12%.

GLOSSARY

Impact Bending — In the impact bending test, a hammer of given weight is dropped upon a beam from successively increased heights until rupture occurs or the beam deflects 152 mm (6 in.) or more. The height of the maximum drop, or the drop that causes failure, is a comparative value that represents the ability of wood to absorb s hocks that cause stresses beyond the proportional limit.

Janka Hardness — Defined as resistance to indentation using a modified Janka hardness test, measured by the load required to embed a 11.28-mm (0.444-in) ball to one-half its diameter. Values presented are the average of radial and tangential penetrations.

Modulus of Elasticity — Elasticity implies that deformations produced by low stress are completely recoverable after loads are removed. When loaded to higher stress levels, plastic deformation or failure occurs.

Specific Gravity - A measure of the ratio of a wood's density as compared to water. If a wood species had the same density as water, the specific gravity would be 1.00.


SOURCES

  1. “Silvics of North America, Hardwoods”. Williams, Robert D. Vol. 2. 391-399. Juglans nigra L. Black Walnut. United States Department of Agriculture. December 1990.
  2. “Black-Walnut”. The Wood Database. Wood-database.com.
  3. “American Walnut”. American Hardwood Export Council. Americanhardwood.org. Accessed Feb. 2021.
  4. “Nuts About Walnuts”. WoodMagazine.com. Accessed Feb. 2021.
  5. Baird Brothers Janka Hardness Scale Bairdbrothers.com
  6. “Walnut Wood”. Vermontwoodsstudios.com. Accessed Feb. 2021.
  7. “Wood Handbook, Wood as an Engineering Material”. fpl.fs.fed.us. April 2010. Accessed Feb. 2021.
  8. “Black Walnut: Why coloration matters”. Woodworkingnetwork.com. Accessed Feb. 2021.