How hard is hackberry wood?

Hackberry has a Janka side-hardness of 880 lbf (3,910 N), per USDA Forest Products Laboratory reference values at 12% moisture content. Mechanically it is a near-twin to ash, working well under both hand and machine tools despite its coarse texture.

Can hackberry be used outdoors?

No. Hackberry is non-durable, and its sapwood stains and gets attacked by insects fast, so it should be kept inside. It is best suited to indoor uses like furniture, cabinetry, millwork, and flooring.

Why is hackberry often spalted, and is that a defect?

Hackberry spalts and blue-stains aggressively, so it has to be milled and dried fast or it spalts on you. That makes it a defect for utility lumber but a feature for character stock, where the spalting commands a premium. Raw Heartwood kiln-dries its urban-salvaged Chicago-area lumber to 6-8% moisture content.

DomesticCeltis occidentalis

Hackberry

Mechanically a near-twin to ash. Lighter in color, cheaper when you can find it.

Hackberry (Celtis occidentalis) is a domestic hardwood with a Janka hardness of 880 lbf. Mechanically a near-twin to ash, it runs yellowish gray to light brown with little contrast between heart and sap, and spalts and blue-stains readily.

Category: Domestic
Janka: 880 lbf
Botanical: Celtis occidentalis
Shipped at: 6–8% MC

Celtis occidentalis Eastern and central United States from New England south to northern Florida and west across the Great Plains into eastern Wyoming and Colorado

Eastern and central United States from New England south to northern Florida and west across the Great Plains into eastern Wyoming and Colorado.

Mechanically a near-twin to ash, lighter in color, cheaper when you can find it. Not much contrast between heart and sap.

Detail of Hackberry grain — figured wood texture, photographed at Raw Heartwood — A close read on the grain. Detail of this specimen

What you see.

Not much contrast between heart and sap. The whole board runs yellowish gray to light brown with subtle yellow streaks. Spalts and blue-stains aggressively — character lumber goes for a premium.

Heartwood color detail of Hackberry (Celtis occidentalis)

Heartwood, this specimen

How the grain runs.

Mostly straight, sometimes slightly interlocked. Moderate to coarse, uneven texture. Ring-porous, so the figure on a sawn face reads a lot like ash or elm.

Closer in

On the bench.

Non-durable. Sapwood stains and bugs out fast. Keep it inside. Good under hand and machine despite the coarse texture. Steam-bends well. Glues without trouble. Stains and finishes readily. Often subbed for ash in furniture parts. Mild. Nothing distinct. Reported skin irritation, uncommon. Same family as elm but the pollen is much milder.

The numbers, looked at directly.

Janka Hardness

0lbf

3,910 N. Side-hardness — force to embed a half-inch steel ball halfway into the wood.

Average Dried Weight

0lbs/ft³

593 kg/m³. At 12% MC.

Specific Gravity

0.49/ 0.53 at 12% MC

Basic over green volume; second number at 12% moisture content.

Hardness, in context

A side-hardness measurement. Higher number, harder wood.

Shrinkage — radial / tangential / volumetric

4.8%radial

8.9%tangential

13.8%volumetric

On sourcing

Where this wood comes from matters.

Not on CITES. Not on the IUCN Red List. Widely distributed and abundant.

What it's for.

Furniture
Cabinetry
Millwork
Flooring
Athletic equipment
Plywood
Spalted craft

Worth knowing.

Mechanically a near-twin to ash, lighter in color, cheaper when you can find it. You have to mill it and dry it fast or it spalts on you. Defect for utility lumber, feature for character stock.

Sources & references.

Wood Handbook — Wood as an Engineering Material (FPL-GTR-282) — USDA Forest Service, Forest Products Laboratory (2021)
Hackberry (Celtis occidentalis) — FPL Tech Sheet — USDA Forest Service, Forest Products Laboratory
Silvics of North America: Celtis occidentalis L. — Hackberry — Krajicek, John E.; Williams, Robert D. (USDA Forest Service) (1990)
Celtis occidentalis — IUCN Red List of Threatened Species — Stritch, L. (2018)
Celtis occidentalis — Wikipedia contributors
Hackberry (Celtis occidentalis) — The Wood Database

Common questions.

How hard is hackberry wood?: Hackberry has a Janka side-hardness of 880 lbf (3,910 N), per USDA Forest Products Laboratory reference values at 12% moisture content. Mechanically it is a near-twin to ash, working well under both hand and machine tools despite its coarse texture.
Can hackberry be used outdoors?: No. Hackberry is non-durable, and its sapwood stains and gets attacked by insects fast, so it should be kept inside. It is best suited to indoor uses like furniture, cabinetry, millwork, and flooring.
Why is hackberry often spalted, and is that a defect?: Hackberry spalts and blue-stains aggressively, so it has to be milled and dried fast or it spalts on you. That makes it a defect for utility lumber but a feature for character stock, where the spalting commands a premium. Raw Heartwood kiln-dries its urban-salvaged Chicago-area lumber to 6-8% moisture content.

From the library to your bench