Lignum Vitae
Guaiacum officinale
Also known as guayacan, ironwood · Botanical Guaiacum officinale
Revision history
- — Data re-verified in site-wide audit (formulas, sources, durability classes)
- — Working properties and comparable-species data cross-checked against listed sources
About Lignum Vitae
Lignum Vitae (Guaiacum officinale) is one of the hardest timbers in commercial use, extremely wear-resistant and dense enough to sink, with a Janka hardness of 4,390 lbf (19,527 N) and a density of about 1.05 g/cm³. It is native to the Caribbean and the northern coast of South America.
At 4.0% radial and 6.5% tangential the T/R ratio is 1.62 — typical, and manageable in exterior joinery and cladding provided the gaps are designed rather than assumed. Its fibre saturation point is near 23%. Below it the wood shrinks steadily — 6.5% tangential, 4.0% radial. Ordinary territory: design the gaps rather than hoping the finish will hold it.5% tangential against 4.0% radial, quartersawn stock will behave noticeably better than flatsawn.
At 1050 kg/m³ a cubic metre of Lignum Vitae weighs about 1050 kg air-dry — that figure, the 6.5% tangential and 4.0% radial movement and the 4,390 lbf hardness are the three inputs the calculators below actually consume. Select Lignum Vitae in any of them to get species-specific results for weight, moisture, shrinkage and hardness.
Working properties
How Lignum Vitae behaves at the bench and on the machine, drawn from international wood-technology databases and marine-engineering references.
Durability & use classification
Lignum Vitae is rated very durable (EN 350 Class 1), and its performance submerged or in ground contact is legendary. The mechanism is unusual and worth understanding: the wood contains guaiac resin, which turns fluid under friction heat and lubricates the wood, then withdraws back into the pores as it cools — genuinely self-lubricating. Sourcing: exploited to the brink, it was among the very first species CITES listed, back in 1975, and all Guaiacum are now Appendix II.
Typical applications & suitability
Indoor Outdoor — An engineering material as much as a timber. Where lubrication is impractical — underwater, inside a bearing — it outperforms materials you would expect to win, reportedly lasting about twice as long as plastic composite bearings.
Documented end-uses: water-lubricated shaft and stern-tube bearings for ships (including the submarines USS Pampanito and the nuclear USS Nautilus), hydroelectric turbine bearings, propeller-shaft and face seals, pulley sheaves and blocks, bearings and gears in John Harrison's marine chronometers, mallets, gem-cutting laps, railway ties (the Panama Railroad), and turned objects.
Comparable species
Species closest to Lignum Vitae by density, hardness, stiffness and bending strength, computed directly from the Vriksai species dataset rather than hand-picked.
Trade alternatives. Beware substitution: verawood / Argentine lignum vitae looks and weighs similar but lacks the true working qualities. Genuine lignum has solitary pores; verawood's are grouped. For comparable density, African Blackwood or Ipe.
Alternatives to Lignum Vitae
Lignum Vitae measures 4,390 lbf Janka at 1.05 g/cm³, EN 350 durability Class 1, movement rated Excellent. Anything replacing Lignum Vitae outdoors has to hold Class 1 durability and carry the load — so nothing below that class appears here, however well it matches on hardness. Read the numbers against the Janka scale and EN 350 durability classes.
Lighter sections, easier fixing and lower freight per m³ — while holding the exterior durability class. Useful where the spec is over-engineered for the actual load.
Exterior sections move most, and a dense timber that moves takes fixings and joints with it. These hold their dimension better in the same durability class. Size the gaps with the shrinkage predictor and EMC calculator.
If Lignum Vitae is unavailable and the specification cannot change, these are the nearest substitutes across hardness, density, movement, stiffness, bending strength and durability class together — not on any single property. Lower distance means a closer match.
Computed from measured properties only — hardness, density, movement, stiffness, bending strength and EN 350 class. Price, availability and appearance are never inputs. Figures are representative values, not consignment absolutes: two species within a few percent are equivalent until verified on the material. Full method and the rules the engine cannot break.
Substituting outdoors is a match on durability class and movement first. Colour and grain can be matched later; a wrong durability class shows up as a callback in three monsoons. Where two candidates are close, compare them directly before specifying.
Compare Lignum Vitae side by side
The pairings below are the ones that actually come up in exterior and structural tendering. Every pairing shows the measured figures side by side; full matrix in the comparison index.
Calculators relevant to Lignum Vitae
Sized for exterior and load-bearing work in Lignum Vitae — spans, fixings, weathering gaps and freight weight. Full set in the tool index.
Understand the figures
Wood density reference — oven-dry vs air-dry basis · Moisture content — EMC, FSP and service conditions · Strength properties — MOR, MOE and what they govern · Durability & fire — EN 350 classes and E84 ratings.
Further reading. Wood moisture content explained · How to calculate board feet.
Common questions about Lignum Vitae
unverified no published source for this figure · FPL USDA FPL Wood Handbook GTR-190 · WD The Wood Database (Eric Meier) · calc derived from the figures above