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Representative source rows, qualified by their reported conditions. Inspect the tables below for all values, limits, and source notes.
ASTM A536 Grade 60-40-18 is the premier high-ductility, high-impact-toughness grade of spheroidal graphite (ductile) cast iron. Formulated with a fully ferritic matrix (>90% ferrite) surrounding Type I and II graphite nodules, it guarantees a minimum tensile strength of 60 ksi (414 MPa), minimum yield strength of 40 ksi (276 MPa), and minimum tensile elongation of 18%. It provides exceptional resistance to mechanical shock and brittle fracture down to -20°C, making it indispensable for pressure vessels, underground water mains, and cold-climate off-highway steering knuckles.
Source-backed commercial trade name and short designations cataloged in canonical data.
Standard Designations & Applicable Specifications — Semantically classified designations distinguishing primary standard identifiers, commercial trade names, and applicable specification references.
| System | Identifier | Standard System Name | Classification Notes & Provenance |
|---|---|---|---|
| ASTMPRIMARY | A536 Grade 60-40-18 | ASTM International | —Ref: Standard Specifications for Gray and Ductile Cast Iron (ASTM A48/A48M, ASTM A536, EN 1561, EN 1563, ISO 185, ISO 1083, SAE J431, SAE J434, ASM Handbook Vol 1) |
| UNS | F32800 | Unified Numbering System | —Ref: Standard Specifications for Gray and Ductile Cast Iron (ASTM A48/A48M, ASTM A536, EN 1561, EN 1563, ISO 185, ISO 1083, SAE J431, SAE J434, ASM Handbook Vol 1) |
| SAE | J434 D4018 | SAE International | —Ref: Standard Specifications for Gray and Ductile Cast Iron (ASTM A48/A48M, ASTM A536, EN 1561, EN 1563, ISO 185, ISO 1083, SAE J431, SAE J434, ASM Handbook Vol 1) |
| Recognized Name / Alias | Classification | Technical Usage & Context |
|---|---|---|
| Ductile Iron 60-40-18 | Commercial Alias | Colloquial or commercial industry synonym |
| Nodular Iron 60-40-18 | Commercial Alias | Colloquial or commercial industry synonym |
| Ferritic Ductile Iron | Colloquial Alias | Colloquial or commercial industry synonym |
| Standards Body | Specification Code | Specification Title / Scope | Relationship Type |
|---|---|---|---|
| ASTM | ASTM A536 | Standard Specification for Ductile Iron Castings | Specification Reference |
| SAE | SAE J434 | Automotive Ductile (Nodular) Iron Castings (Grade D4018) | Specification Reference |
| ISO | ISO 1083 | Spheroidal graphite cast irons — Classification | Specification Reference |
Chemical Composition (Weight %) — Elemental limits and values from the cited source. Preserves exact semantic limits (minimums, maximums, and ranges).
| Element | Symbol | Atomic No. | Semantic Basis | Specified Value | Unit | Metallurgical Notes & Qualification | Data Status |
|---|---|---|---|---|---|---|---|
| Carbon | C | 0 | RANGE | 3.50 – 3.85 | wt% | Ref: ASTM International, CEN, ISO & ASM International Standards Technical Committees | VERIFIED |
| Silicon | Si | 0 | RANGE | 2.20 – 2.80 | wt% | Silicon kept under 2.8% to maintain high sub-zero Charpy impact energy.Ref: ASTM International, CEN, ISO & ASM International Standards Technical Committees | VERIFIED |
| Manganese | Mn | 0 | MAXIMUM | ≤ 0.35 | wt% | Kept low to prevent pearlite formation and maximize ductility.Ref: ASTM International, CEN, ISO & ASM International Standards Technical Committees | VERIFIED |
| Phosphorus | P | 0 | MAXIMUM | ≤ 0.05 | wt% | Ref: ASTM International, CEN, ISO & ASM International Standards Technical Committees | VERIFIED |
| Sulfur | S | 0 | MAXIMUM | ≤ 0.02 | wt% | Ref: ASTM International, CEN, ISO & ASM International Standards Technical Committees | VERIFIED |
| Magnesium | Mg | 0 | RANGE | 0.04 – 0.06 | wt% | Nodulizing agent inducing spheroidal graphite morphology.Ref: ASTM International, CEN, ISO & ASM International Standards Technical Committees | VERIFIED |
| Iron | Fe | 0 | REMAINDER | Remainder | wt% | Ref: ASTM International, CEN, ISO & ASM International Standards Technical Committees | VERIFIED |
Source-specific physical properties. Test temperatures are shown only where reported.
| Property Parameter | Canonical SI Value | Semantic Basis | Test Temperature / Context Range | Source Raw Reference | Source Reference | Status |
|---|---|---|---|---|---|---|
| Density | 7.1 g/cm³ | TYPICAL | 7.1 g/cm³ | ASTM International, CEN & ISO Technical Committees | VERIFIED |
Phase change temperatures, thermal conductivity, specific heat, mean coefficients of thermal expansion across standardized temperature ranges, and recommended thermal processing windows.
| Property Parameter | Canonical SI Value | Semantic Basis | Test Temperature / Context Range | Source Raw Reference | Source Reference | Status |
|---|---|---|---|---|---|---|
| Thermal Conductivity | 36 W/(m·K) | TYPICAL | 36 W/(m·K) | ASTM International, CEN & ISO Technical Committees | VERIFIED | |
| Specific Heat Capacity | 470 J/(kg·K) | TYPICAL | 470 J/(kg·K) | ASTM International, CEN & ISO Technical Committees | VERIFIED | |
| Coefficient of Thermal Expansion | 11.8 µm/(m·K) | TYPICAL | 11.8 µm/(m·K) | ASTM International, CEN & ISO Technical Committees | VERIFIED |
Electrical conductivity and resistivity in their reported units and conditions.
| Property Parameter | Canonical SI Value | Semantic Basis | Test Temperature / Context Range | Source Raw Reference | Source Reference | Status |
|---|---|---|---|---|---|---|
| Electrical Resistivity | 550 nΩ·m | TYPICAL | 550 nΩ·m | ASTM International, CEN & ISO Technical Committees | VERIFIED |
Contextual Mechanical Properties & Tempers: Engineering strength, ductility, and hardness values grouped by product form, temper, and section thickness. Mechanical properties are contextual and not isotropic averages.
| Product Form | Temper / Condition | Section Size | Tensile (UTS) | Yield Strength | Elongation | Shear Strength | Fatigue Strength | Hardness (Scales Preserved) | Status |
|---|---|---|---|---|---|---|---|---|---|
| Separately cast test coupon | Annealed or As-CastSource values and qualifiersUltimate Tensile Strength: ≥ 414 MPa (MINIMUM)Governing minimum tensile strength per ASTM A536 Grade 60-40-18 (60 ksi = 414 MPa).ASTM International, CEN, ISO & ASM International Standards Technical Committees — ASTM A48, ASTM A536, EN 1561, EN 1563, ISO 185, ISO 1083, SAE J431, SAE J434, ASM Handbook Vol 1 | — | ≥ 414 MPa | — | — | — | — | — | VERIFIED |
| Standard Product Form | Annealed or As-CastSource values and qualifiers0.2% Offset Yield Strength: ≥ 276 MPa (MINIMUM)Governing minimum 0.2% offset yield strength per ASTM A536 (40 ksi = 276 MPa).ASTM International, CEN, ISO & ASM International Standards Technical Committees — ASTM A48, ASTM A536, EN 1561, EN 1563, ISO 185, ISO 1083, SAE J431, SAE J434, ASM Handbook Vol 1 Elongation at Break (50 mm): ≥ 18 % (MINIMUM)Governing minimum tensile elongation in 2 inches (50 mm) is 18%.ASTM International, CEN, ISO & ASM International Standards Technical Committees — ASTM A48, ASTM A536, EN 1561, EN 1563, ISO 185, ISO 1083, SAE J431, SAE J434, ASM Handbook Vol 1 Modulus of Elasticity: 169 GPa (TYPICAL)Spheroidal graphite yields substantially higher elastic modulus (~169 GPa) than gray cast iron (~80–120 GPa).ASTM International, CEN, ISO & ASM International Standards Technical Committees — ASTM A48, ASTM A536, EN 1561, EN 1563, ISO 185, ISO 1083, SAE J431, SAE J434, ASM Handbook Vol 1 | — | — | ≥ 276 MPa | ≥ 18 % | — | — | — | VERIFIED |
| Standard Product Form | Annealed or As-CastSource values and qualifiers | — | — | — | — | — | — | 140–185 HBW | VERIFIED |
Machining, joining, forming, and thermal processing ratings cataloged from the cited authoritative technical reference.
Very good machinability (~85% of C36000 baseline). Ferritic matrix provides low cutting forces, but ductile chips require chip breaker tool geometries.
Moderately weldable compared to gray iron. Preheating to 200°C–260°C and nickel-iron (ENiFe-CI) electrodes are recommended, followed by full post-weld annealing (870°C–900°C) to restore maximum ductility in the heat-affected zone.
Full ferritizing anneal: heat to 870°C–900°C (1600°F–1650°F) to dissolve carbides, furnace cool to 700°C (1300°F) and hold to convert pearlite to ferrite, then air cool.
Limited cold coining and localized hydraulic swaging possible due to 18% tensile elongation. Bulk hot forging is not typical.
Comparable Grades & Cross-References: Carefully classified cross-reference relationships for ASTM A536 Grade 60-40-18 Ductile Cast Iron. Comparable does not mean equivalent.
| Related Material | Family | Relationship Classification | Metallurgical Notes & Differences | Status | Action |
|---|---|---|---|---|---|
| ASTM A536 Grade 65-45-12 Ductile Cast Iron | Cast Iron | Commonly Compared | Grade 60-40-18 delivers maximum tensile ductility (18% vs 12%) and superior low-temperature impact toughness, whereas 65-45-12 offers 12% higher yield strength (310 vs 276 MPa) with lower heat treatment costs as-cast.Materials serve different design priorities (e.g. higher strength vs superior corrosion resistance or cost). | VERIFIED | Side-by-Side Compare → |
| EN-GJS-400-18 Ductile Cast Iron | Cast Iron | Approximate Equivalent | Direct trans-Atlantic equivalent: EN-GJS-400-18 (min 400 MPa UTS, 250 MPa YS, 18% elongation) and ASTM A536 60-40-18 (min 414 MPa UTS, 276 MPa YS, 18% elongation) share identical ferritic microstructures and shock-resistant engineering applications.Engineering substitution review required. Design calculations must verify temper, formability, and corrosion limits before specifying as a direct replacement. | VERIFIED | Side-by-Side Compare → |
Contextual technical guides explaining degradation mechanisms, testing methodologies, and selection criteria relevant to ASTM A536 Grade 60-40-18 Ductile Cast Iron.
Cast iron is an indispensable alloy family renowned for superior vibration damping and castability, but its iron matrix and carbon microstructure make it susceptible to atmospheric rust. Restoring rusted cast iron requires understanding how mechanical and chemical methods interact with the underlying metal.
Sources & Provenance Trail: Authoritative reference publications, standards specifications, and data registers cited across this material record.
Authoritative foundry data harmonized across ASTM A48, ASTM A536, EN 1561, EN 1563, ISO 185, ISO 1083, SAE J431, SAE J434, and ASM International Handbook Volume 1 (Properties and Selection: Irons, Steels, and High-Performance Alloys).