Juglans nigra

Black Walnut

American Black Walnut is the chocolate-brown hardwood that built mid-century furniture. Imported into European yards as kiln-dried slabs, it works cleanly and finishes to a deep, warm tone that ages well.

Premium import, sourced outside EuropeFamily: Juglandaceae

Density: 610 kg/m³
Janka: 4,490 N
Stock: 12 pieces

Tree

Native to the eastern United States, not Europe. KORENA sources kiln-dried slabs through established North American timber channels and lands them in EU yards already at furniture moisture content. Expect FAS or better grading on slab stock, with provenance tied to a specific US mill or broker.

Wood appearance

Heartwood ranges from chocolate brown to a purplish or greyish brown, often with darker streaks. Sapwood is pale cream, usually steamed at the mill to even out the contrast, but you'll still see some on wide slabs. Grain is generally straight, though figured boards (curl, crotch, burl) turn up regularly and command a premium. Medium, even texture takes detail well.

Chocolate to purplish-brown heartwood
Pale cream sapwood, often steamed for uniformity
Darker streaks and figure on wider boards
Lightens slightly under UV over the first year
Deepens and warms under oil finishes
Generally straight; can be irregular or wavy. Medium texture.

Mechanical properties

Density (kg/m³)	560–660 kg/m³
Janka hardness (N)	4,100–4,900 N
MOR: modulus of rupture (MPa)	100–110 MPa
MOE: modulus of elasticity (GPa)	11.0–12.0 GPa
Radial shrinkage	5.0–6.0 %
Tangential shrinkage	7.5–8.5 %
Volumetric shrinkage	11.0–12.5 %
Natural durability (EN 350)	Class 2 — Durable

Working with it

1 = difficult · 5 = excellent

Easy across the board. Sawing, planing, sanding, turning and carving all rate 4 out of 5. Glues and screws without complaint. Steam bending is the one weak spot (3/5), workable for gentle curves, not the species you'd choose for tight bentwood seating. Sharp tooling keeps the surface clean; dull blades will burnish rather than tear.

Sawing
Planing
Sanding
Turning
Carving
Gluing
Screw / nail hold
Steam bending

Drying

Slabs arrive kiln-dried to roughly 8–10% MC. Movement in service is moderate, radial 5.0–6.0%, tangential 7.5–8.5%, so wide tops still want a breathable build (breadboard ends, slot-screwed cleats, or fixed-and-floating fasteners). Acclimatise to your shop for two to three weeks before final flattening.

Finishing

Finishes beautifully with very little fuss. Hard wax oil and Danish oil deepen the brown without muddying the grain; a thin shellac seal coat helps if you're spraying lacquer over oily patches. Sanded to 180–220 it feels silky in the hand. Black walnut lightens slightly with UV exposure over the first year, the opposite of cherry, so a UV-inhibiting topcoat helps on pieces near windows.

Durability and safety

Class 2 — Durable
Food contact safe
Dust irritant: wear PPE

Walnut dust contains juglone and is a known respiratory and skin sensitiser. Run a dust extractor at the source and wear a P3/FFP3 mask when sanding. Juglone-laden offcuts and shavings are toxic to horses and to some plants (tomatoes, apples), so don't compost or use as bedding. Cured finished surfaces are food-contact safe.

Best uses

Live-edge dining and conference tables
Mid-century-style casework and credenzas
Dark-toned kitchen islands and breakfast bars
Desks and writing tables with figured tops
Gunstocks, knife scales and high-end tool handles
Turned bowls and hollow forms
Hand-carved sculpture and relief panels
Food-safe serving boards and charcuterie platters

Pairs and substitutes

Pairs well with

Often substituted for

Sourcing and sustainability

Premium import, sourced outside Europe
IUCN: LC — Least Concern

IUCN Least Concern, no CITES listing. Decay class 2 (durable) but this is an indoor wood, the value is in the colour and workability, not outdoor performance. As a North American import, the supplier chain-of-custody back to the mill travels with the slab. EUDR due diligence is in preparation and becomes mandatory for large operators from 30 December 2026, and KORENA is building each slab passport to carry the provenance evidence a buyer will need.

What Black Walnut actually is#

Juglans nigra is the darkest wood in this catalogue and the North American counterpart to European walnut. Where Juglans regia is a lighter grey brown full of streaking, black walnut is a deeper, more uniform chocolate.

The other significant difference is commercial rather than botanical. Black walnut is grown as a forestry species across eastern North America, so it comes in larger, straighter, more consistent sizes than European walnut, much of which is salvaged from orchards and gardens. If you need matched material across several wide boards, black walnut is the easier species to source.

The steaming question, which matters more than most people realise#

A large proportion of commercial black walnut is steamed during kiln drying.

Steaming drives colour out of the dark heartwood and into the pale sapwood. The result is a board that reads more uniformly brown, with the sapwood muddied to a dull tan rather than staying cream. For a factory producing matched furniture components, that uniformity is the point.

For a live edge slab it is usually the opposite of what you want. The sharp contrast between pale cream sapwood and near black heartwood is one of the most striking features this species offers, and steaming destroys it.

Unsteamed black walnut keeps that contrast. It is worth asking which you are being offered, because the difference is permanent and not visible from a description alone.

Reading a Black Walnut slab#

Heartwood runs mid to dark chocolate brown, sometimes with purple or grey undertones when freshly cut. Sapwood is pale cream and, if unsteamed, sharply demarcated.

Grain is usually straight, which makes plain black walnut easier to machine than figured European walnut. Crotch, burl and curly figure occurs and is priced accordingly.

Check whether the sapwood has been steamed by looking at the transition: a sharp line means unsteamed, a blurred or muddy gradient means steamed.

The fading direction#

Black walnut lightens with light exposure. It does not darken.

This is the opposite of oak, cherry and most other furniture timbers, and it consistently surprises people. A slab chosen for its deep near black colour on the day it was surfaced will mellow over the following years toward a warmer, lighter brown, and the contrast with the sapwood will soften as it does.

Plan for the wood the piece will become rather than the wood it is on the bench.

At the bench#

At 4,490 N it is softer than European walnut and noticeably easier on tooling than oak or ash. It machines cleanly, turns and carves well, glues reliably and finishes beautifully.

Straight grained stock gives very little trouble. Figured crotch and burl material tears out and wants light cuts, sharp tooling and a scraper for the final surface.

Oil finishes suit it particularly well and deepen the colour, though bear the fading in mind: an oil that looks perfect on day one is sitting on wood that will lighten underneath it.

The juglone issue#

Black walnut contains juglone and is a documented sensitiser. Skin and respiratory irritation are reported and some woodworkers sensitise over repeated exposure, so extraction and a mask are worth the habit.

Juglone is toxic to many plants, so shavings should not go into mulch or compost. They must never be used as animal bedding, and walnut shavings are specifically associated with laminitis in horses.

Durability and stability#

Decay class 2 makes black walnut genuinely durable, better than European walnut at class 3 and on a par with oak. That is unusual for a furniture hardwood and is part of why it was used for gunstocks and exterior joinery.

Volumetric shrinkage of 11.0 percent is low for this catalogue, with tangential at 7.5 against radial at 5.0 percent. A comparatively narrow differential means it behaves well in wide flatsawn tops.

Where Black Walnut is the right answer#

Fine furniture, wide tabletops, cabinetry, turned and carved work, and any piece where a dark timber is the design intent and consistency across boards matters.

It is the wrong answer where a European supply chain is required, and where the lightening over time would undermine the design.

Sourcing and EUDR#

Not CITES listed and assessed as Least Concern. It is native to eastern North America, so European buyers are generally importing, with the longer documentation chain and higher transport carbon that implies. European grown Juglans nigra exists in small quantities. Where a dark European alternative is acceptable, Juglans regia covers similar ground with a shorter chain.

Buyer questions

How is Black Walnut different from European Walnut?

Black walnut, Juglans nigra, is darker and more uniformly chocolate brown, where European walnut runs lighter grey brown with more streaking and marbling. Black walnut is slightly softer at 4,490 N against 5,410 N but slightly stiffer at 11.0 GPa. Black walnut also comes in larger, more consistent sizes because it is grown as a forestry species rather than an orchard tree.

Is Black Walnut steamed, and does it matter?

Much commercial American black walnut is steamed during drying, which drives colour from the dark heartwood into the pale sapwood and makes the board look more uniformly brown. Unsteamed walnut keeps a sharp contrast between cream sapwood and dark heartwood. For a live edge slab where the sapwood line is a feature, unsteamed is usually what you want, and it is worth asking.

Does Black Walnut fade?

Yes. Like European walnut it lightens with light exposure rather than darkening, mellowing from deep chocolate toward a warmer, lighter brown. This is the opposite of what oak and cherry do. A UV inhibiting finish slows it without stopping it.

Is walnut dust dangerous?

It contains juglone and is a documented sensitiser, with skin and respiratory irritation reported and sensitisation developing in some woodworkers over time. Run extraction and wear a mask. Walnut shavings are also toxic to many plants and must never be used as animal bedding, particularly for horses.

How durable is it?

Decay class 2, which is genuinely durable and better than most furniture hardwoods, including European walnut at class 3. It has been used for exterior joinery and gunstocks partly for that reason. It is still not a species to put in ground contact.

Current stock