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Representative source rows, qualified by their reported conditions. Inspect the tables below for all values, limits, and source notes.
ASTM A48 Class 50 represents the upper tier of high-strength unalloyed to low-alloyed gray cast iron. With a minimum tensile strength of 50 ksi (345 MPa) on Test Bar B, it requires strict metallurgical inoculation and low carbon equivalents to achieve a very fine pearlitic matrix with tightly refined graphite flakes. It delivers exceptional compressive strength (>1100 MPa) and rigidity for high-pressure hydraulic components and heavy mechanical presses.
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 | A48 Class 50 | 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 | F13501 | 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 | J431 G5000 | 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 |
|---|---|---|
| Class 50 Gray Iron | Commercial Alias | Colloquial or commercial industry synonym |
| High-Strength Gray Iron 50 | Colloquial Alias | Colloquial or commercial industry synonym |
| Standards Body | Specification Code | Specification Title / Scope | Relationship Type |
|---|---|---|---|
| ASTM | ASTM A48 / A48M | Standard Specification for Gray Iron Castings | Specification Reference |
| SAE | SAE J431 | Automotive Gray Iron Castings (Grade G5000) | 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 | 2.80 – 3.10 | wt% | Ref: ASTM International, CEN, ISO & ASM International Standards Technical Committees | VERIFIED |
| Silicon | Si | 0 | RANGE | 1.40 – 1.80 | wt% | Ref: ASTM International, CEN, ISO & ASM International Standards Technical Committees | VERIFIED |
| Manganese | Mn | 0 | RANGE | 0.80 – 1.10 | wt% | Ref: ASTM International, CEN, ISO & ASM International Standards Technical Committees | VERIFIED |
| Phosphorus | P | 0 | MAXIMUM | ≤ 0.08 | wt% | Ref: ASTM International, CEN, ISO & ASM International Standards Technical Committees | VERIFIED |
| Sulfur | S | 0 | MAXIMUM | ≤ 0.10 | wt% | Ref: ASTM International, CEN, ISO & ASM International Standards Technical Committees | VERIFIED |
| Molybdenum | Mo | 0 | RANGE | 0.20 – 0.50 | wt% | Optional alloy addition for elevated temperature strength.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 | 7.3 g/cm³ | TYPICAL | 7.3 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 | 40 W/(m·K) | TYPICAL | 40 W/(m·K) | ASTM International, CEN & ISO Technical Committees | VERIFIED | |
| Specific Heat Capacity | 500 J/(kg·K) | TYPICAL | 500 J/(kg·K) | ASTM International, CEN & ISO Technical Committees | VERIFIED | |
| Coefficient of Thermal Expansion | 10.5 µm/(m·K) | TYPICAL | 10.5 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 | 580 nΩ·m | TYPICAL | 580 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 |
|---|---|---|---|---|---|---|---|---|---|
| Standard Product Form | As-CastSource values and qualifiersUltimate Tensile Strength: ≥ 345 MPa (MINIMUM)Governing minimum tensile strength per ASTM A48 Class 50 (50 ksi = 345 MPa). No distinct yield point.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 | 30.5 mm Test Bar B | ≥ 345 MPa | — | — | — | — | — | VERIFIED |
| Standard Product Form | As-CastSource values and qualifiers | — | — | — | — | — | — | — | VERIFIED |
| Standard Product Form | As-CastSource values and qualifiers | — | — | — | — | — | — | 240–290 HBW | VERIFIED |
Machining, joining, forming, and thermal processing ratings cataloged from the cited authoritative technical reference.
Moderate machinability (~60% relative to C36000 baseline). High hardness (240–290 HBW) and dense pearlitic matrix necessitate rigid setups and ceramic or CBN tooling for finishing.
Extremely poor weldability. Highly prone to cracking and chilling; fusion welding is not recommended for production components.
Stress relief annealing at 595°C–620°C for 2 hours. Induction hardening yields up to 58–60 HRC.
Non-deformable. Cast iron lacks tensile ductility.
Comparable Grades & Cross-References: Carefully classified cross-reference relationships for ASTM A48 Class 50 Gray Cast Iron. Comparable does not mean equivalent.
| Related Material | Family | Relationship Classification | Metallurgical Notes & Differences | Status | Action |
|---|---|---|---|---|---|
| ASTM A536 Grade 80-55-06 Ductile Cast Iron | Cast Iron | Commonly Compared | High-strength selection: Class 50 Gray Iron delivers maximum damping and compressive rigidity without magnesium nodulizing treatments, whereas 80-55-06 Ductile Iron offers 60% higher tensile strength (552 vs 345 MPa) and 6% elongation.Materials serve different design priorities (e.g. higher strength vs superior corrosion resistance or cost). | VERIFIED | Side-by-Side Compare → |
Contextual technical guides explaining degradation mechanisms, testing methodologies, and selection criteria relevant to ASTM A48 Class 50 Gray 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).