Robinia pseudoacacia

Black Locust / Robinia

Class 1 durability from a tree that grows in Europe. One of the only EU-native options that survives outdoors untreated, and a credible domestic answer to tropical exotics like teak.

Grown commercially in EuropeFamily: Fabaceae

Tree

Originally North American, but naturalised and commercially grown across central and eastern Europe for over two centuries. Hungary, Romania, Bulgaria, and Slovakia all have working forestry programmes around it. For sourcing and EUDR purposes we treat it as European stock — the supply chain sits inside the EU and the paperwork follows.

Wood appearance

Straight grain, coarse open texture, and a heartwood that lands somewhere between olive-yellow and greenish-gold when freshly cut. UV does the work over the next few months — the green calms down and the wood warms into a deep amber. Sapwood is narrow and pale yellow. The contrast between the two reads cleanly on wide slabs.

Olive-yellow to greenish-gold heartwood when freshly milled
Warms to a deep amber over weeks of light exposure
Narrow pale yellow sapwood, cleanly demarcated from the heartwood
Coarse open pores read clearly under oil finishes
Straight grain, coarse texture; very durable.

Mechanical properties

Density (kg/m³)	700–830 kg/m³
Janka hardness (N)	7,000–8,200 N
MOR: modulus of rupture (MPa)	130–150 MPa
MOE: modulus of elasticity (GPa)	14.0–16.0 GPa
Radial shrinkage	4.0–5.0 %
Tangential shrinkage	6.5–8.0 %
Volumetric shrinkage	10.0–12.0 %
Natural durability (EN 350)	Class 1 — Very durable

Working with it

1 = difficult · 5 = excellent

Honest warning — this is a hard, tough wood and it will blunt edges. Carbide tooling is sensible, and HSS needs frequent sharpening. Sawing, planing, and sanding all sit around average difficulty for the effort, but tool wear is well above average. It glues and screws cleanly once you pre-drill, and it turns nicely. The standout is steam-bending — Robinia is one of the best European species for it, on a par with white oak.

Sawing
Planing
Sanding
Turning

Drying

Dries slowly and benefits from patience. Surprisingly stable for its hardness once acclimatised — radial movement around 4–5% and tangential 6.5–8% are modest for a 770 kg/m³ wood. Stack with care, weight the top, and expect some end-checking if rushed. Kiln schedules should be conservative.

Finishing

Takes oils and hardwax oils well; the open pores welcome them. The early colour shift is dramatic, so finish a test piece and leave it in daylight for a fortnight before committing — what you see on the bench is not what the client will see in a month. UV-blocking finishes slow the amber drift if a greener tone is wanted. Sanding to 180 is usually enough; finer grits can burnish the surface and fight oil uptake.

Durability and safety

Class 1 — Very durable
Food contact not specified
Dust irritant: wear PPE

Not recommended for direct food contact. The bark, leaves, and seeds carry toxic compounds, and while the heartwood is considered the safer part of the tree, we would not specify it for cutting boards or utensils. The dust is a known irritant and sensitiser — some woodworkers report nausea from prolonged exposure. Run dust extraction and a fitted respirator, not just a paper mask.

Best uses

Outdoor benches and garden furniture that need to survive without preservative treatment
Thresholds, sills, and entry pieces that take weather and wear
Fence posts and landscape elements designed as visible objects, not buried hardware
High-wear interior tops — kitchen islands, workshop benches, retail counters
Tool handles and turned forms where toughness matters
Steam-bent components — chair backs, hoops, curved frames

Pairs and substitutes

Pairs well with

Often substituted for

Sourcing and sustainability

Grown commercially in Europe
IUCN: LC — Least Concern

IUCN Least Concern, no CITES listing. Grown commercially across central and eastern EU, often on marginal land where slower-growing natives struggle. Class 1 durability means outdoor pieces last decades without preservative chemistry, which is its own sustainability argument. EUDR-wise, the supply chain is short and EU-internal — provenance is straightforward to document.

Buyer questions

Is Black Locust / Robinia a good choice for furniture?

Black Locust / Robinia is best matched to projects such as Outdoor benches and garden furniture that need to survive without preservative treatment, Thresholds, sills, and entry pieces that take weather and wear, Fence posts and landscape elements designed as visible objects, not buried hardware, High-wear interior tops — kitchen islands, workshop benches, retail counters, Tool handles and turned forms where toughness matters, Steam-bent components — chair backs, hoops, curved frames. The final choice should consider grain, finish, movement allowance, and the room where the piece will live.

How hard is Black Locust / Robinia?

The listed Janka value is 7,560 N and the density is 770 kg/m³. Use these as comparison signals, not as a guarantee of how a finished surface will wear.

What should I check before buying Black Locust / Robinia slabs online?

Check measured length, width stations, thickness, drying method, moisture notes, colour variation, defects, and origin. Compare the measured outline against the finished drawing before reserving the slab.

Current stock