Maple HARD-KD
Grade · default condition
HARD-KD = hard maple, kiln-dried
Default choice for flooring, butcher block, bowling pins, instrument necks and tooling jigs where hardness and dimensional stability matter.
Values for the HARD-KD condition
Other Maple tempers and conditions
Maple is listed in 3 conditions; see the grade overview at Maple.
- HARD-GREEN
- SOFT-KD
- HARD-KD
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hard maple, green (above fibre saturation, ~ 65 % MC) | Freshly sawn stock for turning, steam-bending or resawing before drying; strength and stiffness are markedly lower and shrinkage is still to come. | — | 70 | — | — | 0.32 W/m·K |
Soft maple, kiln-dried | Pick when cost and easier machining matter more than wear resistance — painted furniture, mouldings, jig bodies, drawer sides. | — | 85 | — | — | 0.14 W/m·K |
HARD-KDDefaultThis page Hard maple, kiln-dried | Default choice for flooring, butcher block, bowling pins, instrument necks and tooling jigs where hardness and dimensional stability matter. | — | 100 | 1.5 | — | 0.16 W/m·K |
What is Maple HARD-KD?
Maple HARD-KD is Maple in the HARD-KD grade — default choice for flooring, butcher block, bowling pins, instrument necks and tooling jigs where hardness and dimensional stability matter. Maple HARD-KD has a tensile strength of 100 MPa (14.5 ksi), stronger than 85% of natural material grades. Elongation at break is 1.5% and the elastic modulus is 12.6 GPa (1.83 Msi). Maple HARD-KD has a density of 0.71 g/cm³ (0.0255 lb/in³), heavier than 57% of natural material grades.
Advantages
- Polishes to a fine finish — 88/100, better than 94% of natural material grades
Maple HARD-KD properties
Typical room-temperature values for Maple HARD-KD; 13 are specific to this condition. Other listed values are Maple reference data and may not represent this condition. Bars are the position among natural material grades.
Physical2
Maple HARD-KD has a density of 0.71 g/cm³ (0.0255 lb/in³), heavier than 57% of natural material grades.
Mechanical9
Maple HARD-KD has a tensile strength of 100 MPa (14.5 ksi), stronger than 85% of natural material grades. Elongation at break is 1.5% and the elastic modulus is 12.6 GPa (1.83 Msi).
Thermal5
Maple HARD-KD is rated for continuous service to 90°C (194 °F). It conducts heat at 0.16 W/m·K (0.0924 BTU/hr·ft·°F), better than 64% of natural material grades. Thermal expansion is 4 µm/m·K (2.22 µin/in·°F).
Electrical2
Maple HARD-KD is an electrical insulator with a dielectric strength of 4 kV/mm (101.6 V/mil) and a resistivity of 1×10⁸ Ω·m.
Chemical & Environmental1
Corrosion resistance is fair (45/100), better than 53% of natural material grades.
Sustainability4
Producing a kilogram of Maple HARD-KD takes about 10 MJ of energy and emits 0.45 kg of CO₂ — less than 56% of natural material grades. Typical recycled content is 5%.
Manufacturability2
Maple HARD-KD's machinability is good (68/100, worse than 74% of natural material grades).
Common Calculations4
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Maple HARD-KD
Is Maple easy to machine?
Cuts and turns cleanly with carbide tooling, but low feed rates cause scorching — use sharp tools, high SFM with adequate chip clearance and light finishing passes.
Can Maple be welded?
Not weldable; joined by PVA/epoxy/polyurethane adhesives or mechanical fasteners with pre-drilled pilot holes to avoid splitting.
Can Maple be formed, bent or molded?
Steam-bends moderately well (hard maple is only fair, soft maple better); air/kiln-dry to 6–8 % MC and allow for ~9 % tangential shrinkage before machining critical dimensions.
What surface finishes work on Maple?
Dense closed pores blotch with pigment stains — use a washcoat/gel stain or dye; sands to a very fine surface and takes lacquer, oil or waterborne finishes to a high sheen.
Maple 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 |
|---|---|---|
| cellulosestructural microfibrils | 42 – 48 | 45 |
| hemicellulosemainly glucuronoxylan (hardwood) | 25 – 32 | 29 |
| ligninsyringyl/guaiacyl type | 20 – 25 | 22 |
| extractivessugars, phenolics; low in maple | 1.5 – 4.5 | 3 |
| ashCa/K minerals | 0.2 – 0.6 | 0.4 |
| moisturekiln-dried indoor EMC basis | 6 – 12 | 8 |
Maple HARD-KD — frequently asked
What is Maple HARD-KD used for?
Maple HARD-KD is typically used for flooring, bowling pins/lanes, musical instruments, cutting boards and furniture. In short: hardest common temperate hardwood; clean-machining closed-grain surface; high shock resistance.
What is the tensile strength of Maple HARD-KD?
Maple HARD-KD has a typical tensile strength of 100 MPa (14.5 ksi) — stronger than 85% of natural material grades. Strength varies by condition: see the 3 listed tempers.
Is Maple HARD-KD easy to machine?
Reasonably — machinability is rated good (68/100, worse than 74% of natural material grades). Cuts and turns cleanly with carbide tooling, but low feed rates cause scorching — use sharp tools, high SFM with adequate chip clearance and light finishing passes.
Can Maple HARD-KD be welded?
Not weldable; joined by PVA/epoxy/polyurethane adhesives or mechanical fasteners with pre-drilled pilot holes to avoid splitting.
What surface finishes work on Maple HARD-KD?
Dense closed pores blotch with pigment stains — use a washcoat/gel stain or dye; sands to a very fine surface and takes lacquer, oil or waterborne finishes to a high sheen.
Can Maple HARD-KD be formed, bent or molded?
Steam-bends moderately well (hard maple is only fair, soft maple better); air/kiln-dry to 6–8 % MC and allow for ~9 % tangential shrinkage before machining critical dimensions.
What is the maximum service temperature of Maple HARD-KD?
Maple HARD-KD 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-190, Ch.5 Mechanical Properties — USDA Forest Products Laboratory (2021)
- EN 13556 — Round and sawn timber: nomenclature of timbers used in Europe (ACSA/ACRU codes) — CEN (2003)
- ASTM D143 — Standard Test Methods for Small Clear Specimens of Timber — ASTM International (2022)
- NHLA Rules for the Measurement and Inspection of Hardwood Lumber — National Hardwood Lumber Association (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.