Limestone HD (Class III HD)
Supply condition
ASTM C568
Dense, low-absorption limestone for heavy-traffic paving, stair treads and severe-exposure cladding; takes a honed/near-polished finish.
Values for the HD condition
Other Limestone tempers and conditions
Limestone is listed in 4 conditions; see the grade overview at Limestone.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Class I LD | Soft, porous, easily carved stone for interior work and protected exterior detailing. | — | 3 | — | — | 1 W/m·K |
MDDefault Class II MD | The standard building limestone (e.g. Indiana-type) for cladding, sills and pavers — best balance of workability and durability. | — | 5 | — | — | 2 W/m·K |
HDThis page Class III HD | Dense, low-absorption limestone for heavy-traffic paving, stair treads and severe-exposure cladding; takes a honed/near-polished finish. | — | 8 | — | — | 3 W/m·K |
Dolomitic limestone | Choose when higher hardness, better acid resistance and a tighter polish than ordinary calcitic limestone are required. | — | — | — | — | 3 W/m·K |
What is Limestone HD?
Limestone HD is Limestone supplied in the HD condition — dense, low-absorption limestone for heavy-traffic paving, stair treads and severe-exposure cladding; takes a honed/near-polished finish. Limestone HD has a tensile strength of 8 MPa (1.16 ksi), weaker than 78% of natural material grades. Elongation at break is 0.05% and the elastic modulus is 55 GPa (7.98 Msi). Limestone HD has a density of 2.65 g/cm³ (0.0957 lb/in³), heavier than 87% of natural material grades. MD is the default condition FabDigit quotes; HD is available on request or by drawing note.
Advantages
- Low embodied carbon — 0.09 kg CO₂/kg, better than 95% of natural material grades
- High service temperature — 400°C (752 °F), better than 94% of natural material grades
- Conducts heat well — 2.5 W/m·K (1.44 BTU/hr·ft·°F), better than 94% of natural material grades
- Stiff — 55 GPa (7.98 Msi), better than 91% of natural material grades
- Tough — resists crack growth — 0.7 MPa·√m (0.637 ksi·√in), better than 78% of natural material grades
Limitations
- Limited ductility — 0.05%, worse than 94% of natural material grades
- Difficult to machine — 60/100, worse than 89% of natural material grades
- Heavy — 2.65 g/cm³ (0.0957 lb/in³), worse than 87% of natural material grades
- Needs corrosion protection — 30/100, worse than 77% of natural material grades
Limestone HD properties
Typical room-temperature values for Limestone HD; 14 are specific to this condition. Other listed values are Limestone reference data and may not represent this condition. Bars are the position among natural material grades.
Physical2
Limestone HD has a density of 2.65 g/cm³ (0.0957 lb/in³), heavier than 87% of natural material grades.
Mechanical12
Limestone HD has a tensile strength of 8 MPa (1.16 ksi), weaker than 78% of natural material grades. Elongation at break is 0.05% and the elastic modulus is 55 GPa (7.98 Msi).
Thermal5
Limestone HD is rated for continuous service to 400°C (752 °F). It conducts heat at 2.5 W/m·K (1.44 BTU/hr·ft·°F), better than 94% of natural material grades. Thermal expansion is 6 µm/m·K (3.33 µin/in·°F).
Electrical1
Limestone HD has an electrical resistivity of 10,000 Ω·m.
Chemical & Environmental1
Corrosion resistance is poor (30/100), worse than 77% of natural material grades.
Sustainability4
Producing a kilogram of Limestone HD takes about 1 MJ of energy and emits 0.09 kg of CO₂ — less than 96% of natural material grades. Typical recycled content is 0%.
Manufacturability2
Limestone HD's machinability is good (60/100, worse than 89% of natural material grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Limestone HD
Is Limestone easy to machine?
Saws, drills and CNC-carves easily with water-cooled diamond tooling; avoid dry cutting (silica/carbonate dust) and support thin sections against chipping.
Can Limestone be welded?
Not weldable — units are joined with mortar, epoxy/polyester stone adhesives and stainless anchors, dowels or kerf clips.
Can Limestone be formed, bent or molded?
Shaped by quarry block sawing, splitting along bed planes, profiling and hand or CNC carving; never bent or thermally formed.
What surface finishes work on Limestone?
Common finishes are sawn, honed, bush-hammered, sandblasted or tumbled; true high polish only on dense/dolomitic stone, and breathable impregnating sealers are advised against staining and acid rain etch.
Limestone 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 |
|---|---|---|
| CaCO3 (calcite)principal mineral phase | 80 – 99 | 94 |
| MgCO3 (dolomite)up to ~45 % in dolomitic variants | 0.2 – 8 | 2 |
| SiO2quartz/chert impurity | 0.2 – 8 | 2 |
| Al2O3clay minerals | 0.1 – 3 | 0.8 |
| Fe2O3iron oxide, source of buff/tan coloration | 0.05 – 1.5 | 0.3 |
| organic matter / bitumengives grey-blue tones | 0 – 1 | 0.2 |
Limestone HD — frequently asked
What is Limestone HD used for?
Limestone HD is typically used for building facades, flooring and wall cladding, interior decorative trim, landscape and garden features and raw material for lime/cement. In short: easiest-carving building stone; lowest strength stone here; acid-sensitive carbonate stone.
What is the tensile strength of Limestone HD?
Limestone HD has a typical tensile strength of 8 MPa (1.16 ksi) — weaker than 78% of natural material grades. Strength varies by condition: see the 4 listed tempers.
Is Limestone HD easy to machine?
Reasonably — machinability is rated good (60/100, worse than 89% of natural material grades). Saws, drills and CNC-carves easily with water-cooled diamond tooling; avoid dry cutting (silica/carbonate dust) and support thin sections against chipping.
Can Limestone HD be welded?
Not weldable — units are joined with mortar, epoxy/polyester stone adhesives and stainless anchors, dowels or kerf clips.
What surface finishes work on Limestone HD?
Common finishes are sawn, honed, bush-hammered, sandblasted or tumbled; true high polish only on dense/dolomitic stone, and breathable impregnating sealers are advised against staining and acid rain etch.
Can Limestone HD be formed, bent or molded?
Shaped by quarry block sawing, splitting along bed planes, profiling and hand or CNC carving; never bent or thermally formed.
What is the maximum service temperature of Limestone HD?
Limestone HD is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM C568/C568M — Standard Specification for Limestone Dimension Stone — ASTM International (2021)
- ASTM C97 (absorption & bulk density), C99/C880 (modulus of rupture/flexural), C170 (compressive strength) — ASTM International (2018)
- Dimension Stone Design Manual — Natural Stone Institute (MIA+BSI) (2016)
- Indiana Limestone Handbook — Indiana Limestone Institute of America (2007)
- Inventory of Carbon & Energy (ICE) — stone products — University of Bath / Circular Ecology (2019)
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.