Oak RO (Red oak)
Grade
Cheaper, slightly softer and more open-pored than white oak; fine for interior furniture and flooring but not for wet or outdoor use.
Values for the RO condition
Other Oak tempers and conditions
Oak is listed in 3 conditions; see the grade overview at Oak.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Freshly sawn, MC above fibre saturation | Choose only for wet-service or riving/steam-bending work; strength and stiffness are 30–45 % below dry values and shrinkage is still to come. | — | 70 | 1.4 | — | 0.35 W/m·K |
ROThis page Red oak | Cheaper, slightly softer and more open-pored than white oak; fine for interior furniture and flooring but not for wet or outdoor use. | — | 92 | 1 | — | 0.17 W/m·K |
White oak | Pick white oak when liquid-tightness, steam-bending or outdoor decay resistance matters (tyloses-blocked pores, DC2 heartwood). | — | 100 | 1 | — | 0.18 W/m·K |
What is Oak RO?
Oak RO is Oak in the RO grade — cheaper, slightly softer and more open-pored than white oak; fine for interior furniture and flooring but not for wet or outdoor use. Oak RO has a tensile strength of 92 MPa (13.3 ksi), stronger than 77% of natural material grades. Elongation at break is 1% and the elastic modulus is 12.5 GPa (1.81 Msi). Oak RO has a density of 0.7 g/cm³ (0.0253 lb/in³), heavier than 53% of natural material grades.
Advantages
- Conducts heat well — 0.17 W/m·K (0.0982 BTU/hr·ft·°F), better than 76% of natural material grades
Limitations
- Needs corrosion protection — 30/100, worse than 77% of natural material grades
Oak RO properties
Typical room-temperature values for Oak RO; 14 are specific to this condition. Other listed values are Oak reference data and may not represent this condition. Bars are the position among natural material grades.
Physical2
Oak RO has a density of 0.7 g/cm³ (0.0253 lb/in³), heavier than 53% of natural material grades.
Mechanical10
Oak RO has a tensile strength of 92 MPa (13.3 ksi), stronger than 77% of natural material grades. Elongation at break is 1% and the elastic modulus is 12.5 GPa (1.81 Msi).
Thermal5
Oak RO is rated for continuous service to 90°C (194 °F). It conducts heat at 0.17 W/m·K (0.0982 BTU/hr·ft·°F), better than 76% of natural material grades. Thermal expansion is 4.5 µm/m·K (2.5 µin/in·°F).
Electrical2
Oak RO is an electrical insulator with a dielectric strength of 4 kV/mm (101.6 V/mil) and a resistivity of 1×10¹⁰ Ω·m.
Chemical & Environmental1
Corrosion resistance is poor (30/100), worse than 77% of natural material grades.
Sustainability4
Producing a kilogram of Oak RO takes about 11 MJ of energy and emits 0.55 kg of CO₂ — more than 56% of natural material grades. Typical recycled content is 5%.
Manufacturability2
Oak RO's machinability is very good (72/100, worse than 60% of natural material grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Oak RO
Is Oak easy to machine?
Cuts, turns and bores cleanly with carbide tooling and 20–25° rake; high silica-free but abrasive tannin/density causes moderate tool wear, and torn grain around rays needs sharp knives and light finishing cuts.
Can Oak be welded?
Not weldable — joined by PVA/PU/epoxy adhesives or mechanical joinery; pre-bore for screws and use stainless or hot-dip galvanised fasteners because tannins corrode plain steel and cause black staining.
Can Oak be formed, bent or molded?
White oak is one of the best steam-bending hardwoods (radius down to ~2–3× thickness with a compression strap); red oak bends poorly and splits, and all oak must be dried slowly to avoid honeycomb and surface checking.
What surface finishes work on Oak?
Sands and stains readily but the open ring-porous grain needs a pore filler for a mirror finish; ammonia fuming or iron-acetate reacts with tannins for classic darkening, and oil, wax, lacquer or 2K PU all adhere well.
Oak chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| celluloseoven-dry wood basis | 40 – 47 | 44 |
| hemicellulosemainly glucuronoxylan in hardwoods | 18 – 26 | 22 |
| ligninsyringyl/guaiacyl hardwood lignin | 20 – 28 | 24 |
| extractives (tannins, phenolics)high ellagitannin content; stains steel and darkens with iron | 2 – 10 | 6 |
| ash (inorganics) | 0.2 – 0.8 | 0.4 |
| organic matrixbalance of cell-wall constituents | balance | — |
Oak RO — frequently asked
What is Oak RO used for?
Oak RO is typically used for flooring, furniture, cabinetry, barrel staves and structural beams. In short: benchmark structural hardwood; best steam-bending hardwood; hard-wearing flooring choice.
What is the tensile strength of Oak RO?
Oak RO has a typical tensile strength of 92 MPa (13.3 ksi) — stronger than 77% of natural material grades. Strength varies by condition: see the 3 listed tempers.
Is Oak RO easy to machine?
Yes — machinability is rated very good (72/100, worse than 60% of natural material grades). Cuts, turns and bores cleanly with carbide tooling and 20–25° rake; high silica-free but abrasive tannin/density causes moderate tool wear, and torn grain around rays needs sharp knives and light finishing cuts.
Can Oak RO be welded?
Not weldable — joined by PVA/PU/epoxy adhesives or mechanical joinery; pre-bore for screws and use stainless or hot-dip galvanised fasteners because tannins corrode plain steel and cause black staining.
What surface finishes work on Oak RO?
Sands and stains readily but the open ring-porous grain needs a pore filler for a mirror finish; ammonia fuming or iron-acetate reacts with tannins for classic darkening, and oil, wax, lacquer or 2K PU all adhere well.
Can Oak RO be formed, bent or molded?
White oak is one of the best steam-bending hardwoods (radius down to ~2–3× thickness with a compression strap); red oak bends poorly and splits, and all oak must be dried slowly to avoid honeycomb and surface checking.
What is the maximum service temperature of Oak RO?
Oak RO is rated for continuous use to about 90°C (194 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- Wood Handbook — Wood as an Engineering Material (FPL-GTR-282), Ch. 5 Mechanical Properties — USDA Forest Products Laboratory (2021)
- ASTM D143 — Standard Test Methods for Small Clear Specimens of Timber — ASTM International (2022)
- ASTM D9 — Standard Terminology Relating to Wood and Wood-Based Products — ASTM International (2021)
- EN 13556 — Round and sawn timber: nomenclature of timbers used in Europe (QURO / QUPE) — CEN (2003)
- EN 350 — Durability of wood and wood-based products: natural durability classes — CEN (2016)
- CES EduPack eco-audit data, hardwood (oak) lumber — Granta/Ansys (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.