Gray, Ductile and Malleable Cast Iron: Grade Selection Explained
Graphite structure, casting section and test-coupon scope matter more than a familiar class number.
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Representative source rows, qualified by their reported conditions. Inspect the tables below for all values, limits, and source notes.
EN-GJS-500-7 (material number EN-JS1050 / former DIN GGG-50) is Europe's most prominent workhorse ductile cast iron grade. With a balanced ferritic-pearlitic matrix structure (approx. 50% ferrite and 50% pearlite), it specifies a minimum tensile strength of 500 MPa, minimum 0.2% proof strength of 320 MPa, and minimum elongation of 7.0% (for thickness ≤30 mm). Extensively specified across the European automotive and machinery industries for crankshafts, wheel hubs, planetary carriers, and heavy industrial machinery.
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 |
|---|---|---|---|
| ENPRIMARY | EN-GJS-500-7 | European Standard | —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) |
| W-Nr | EN-JS1050 | Werkstoffnummer | —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) |
| DIN | GGG-50 | Deutsches Institut für Normung | —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) |
| ISO | 1083/JS/500-7 | International Organization for Standardization | —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 |
|---|---|---|
| GGG-50 | Historical Alias | Colloquial or commercial industry synonym |
| EN-JS1050 | Commercial Alias | Colloquial or commercial industry synonym |
| Ductile Iron 500-7 | Colloquial Alias | Colloquial or commercial industry synonym |
| Standards Body | Specification Code | Specification Title / Scope | Relationship Type |
|---|---|---|---|
| CEN | EN 1563 | Founding — Spheroidal graphite cast irons | 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 – 3.80 | wt% | Ref: ASTM International, CEN, ISO & ASM International Standards Technical Committees | VERIFIED |
| Silicon | Si | 0 | RANGE | 2.20 – 2.70 | wt% | Ref: ASTM International, CEN, ISO & ASM International Standards Technical Committees | VERIFIED |
| Manganese | Mn | 0 | RANGE | 0.30 – 0.60 | wt% | 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% | 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 | 7.15 g/cm³ | TYPICAL | 7.15 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 | 34 W/(m·K) | TYPICAL | 34 W/(m·K) | ASTM International, CEN & ISO Technical Committees | VERIFIED | |
| Specific Heat Capacity | 475 J/(kg·K) | TYPICAL | 475 J/(kg·K) | ASTM International, CEN & ISO Technical Committees | VERIFIED | |
| Coefficient of Thermal Expansion | 11.6 µm/(m·K) | TYPICAL | 11.6 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 | 570 nΩ·m | TYPICAL | 570 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 | Ferritic-PearliticSource values and qualifiersUltimate Tensile Strength: ≥ 500 MPa (MINIMUM)Governing minimum tensile strength per EN 1563 for wall thickness <= 30 mm.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 0.2% Proof Strength: ≥ 320 MPa (MINIMUM)Governing minimum 0.2% proof stress (Rp0.2) per EN 1563.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 (Lo = 5d): ≥ 7 % (MINIMUM)Minimum elongation per EN 1563 is 7.0%.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 mm wall thickness | ≥ 500 MPa | ≥ 320 MPa | ≥ 7 % | — | — | — | VERIFIED |
| Standard Product Form | Ferritic-PearliticSource values and qualifiers | — | — | — | — | — | — | — | VERIFIED |
| Standard Product Form | Ferritic-PearliticSource values and qualifiers | — | — | — | — | — | — | 170–230 HBW | VERIFIED |
Machining, joining, forming, and thermal processing ratings cataloged from the cited authoritative technical reference.
Good machinability (~75% of C36000 baseline). Mixed ferritic-pearlitic structure delivers smooth finishes and moderate tool life.
Difficult to weld. Preheat to 250°C and use nickel-iron (ENiFe-CI) electrodes with controlled interpass temperatures.
Typically used as-cast. Normalizing from 900°C increases pearlite and strength.
Limited localized deformation only.
By Mat Grades Editorial Desk · Updated 2026-11-14. Use alongside the specified product standard and supplier certificate.
The cataloged machining note for EN-GJS-500-7 Ductile Cast Iron states: Good machinability (~75% of C36000 baseline). Mixed ferritic-pearlitic structure delivers smooth finishes and moderate tool life. A relevant hardness example is HBW Hardness: 170–230 HBW (range; Ferritic-Pearlitic). Use that supplied condition for a trial of the difficult feature. Record tool changes, burr removal, unclamped dimensions and accepted parts per hour. Relative machinability ratings from different reference scales should not be compared as if they were one common test.
The available joining assessment states: Difficult to weld. Preheat to 250°C and use nickel-iron (ENiFe-CI) electrodes with controlled interpass temperatures. The first cataloged strength example is Ultimate Tensile Strength: minimum 500 MPa (minimum; Ferritic-Pearlitic). Assess the final part after joining or thermal processing. Include distortion, cleanup and inspection in the quotation. A material designation or favorable process rating is a starting point for qualification, not evidence that an untested joint meets the drawing.
Consider moisture, coating, local tensile stress and impact as well as the cast-iron family. Surface protection does not repair porosity or a highly stressed transition. Casting section and sampling arrangement affect how coupon evidence relates to the finished component; keep those limits visible in the approval. The recorded thermal example is Thermal Conductivity: 34 W/(m·K) (typical; additional condition not stated). State the exposure and inspection access in the design record so that a change of installation or cleaning method triggers a review. The selected composition entries are C 3.5–3.8 wt%, Si 2.2–2.7 wt%, Mn 0.3–0.6 wt%. Chemistry documents identity; it does not establish fluid compatibility.
Use EN EN-GJS-500-7, W-Nr EN-JS1050, DIN GGG-50 to identify the candidate, then specify the product form and delivered condition separately. The catalog lists Commercial vehicle wheel hubs, steering knuckles, and brake caliper bodies as an application example. The related candidate ASTM A536 Grade 80-55-06 Ductile Cast Iron is linked for comparison; its approximate equivalent relationship must be checked before substitution. Compare the complete route through machining, joining, finish and inspection. Keep the certificate, required test location and acceptance criteria with the first-article record. A later change of grade, condition or source should be assessed against that same requirement.
Technical references: ASTM International, CEN, ISO & ASM International Standards Technical Committees
Comparable Grades & Cross-References: Carefully classified cross-reference relationships for EN-GJS-500-7 Ductile 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 | Approximate Equivalent | EN-GJS-500-7 (min 500 MPa UTS, 320 MPa YS, 7% elongation) and ASTM A536 80-55-06 (min 552 MPa UTS, 379 MPa YS, 6% elongation) occupy comparable medium-strength engineering positions with mixed ferritic-pearlitic matrices.Engineering substitution review required. Design calculations must verify temper, formability, and corrosion limits before specifying as a direct replacement. | VERIFIED | |
| EN-GJS-600-3 Ductile Cast Iron | Cast Iron | Commonly Compared | EN-GJS-500-7 provides higher impact elongation (7% vs 3%), whereas EN-GJS-600-3 provides higher proof stress (370 vs 320 MPa) and better abrasive wear endurance.Materials serve different design priorities (e.g. higher strength vs superior corrosion resistance or cost). | VERIFIED |
Contextual technical guides explaining degradation mechanisms, testing methodologies, and selection criteria relevant to EN-GJS-500-7 Ductile Cast Iron.
Graphite structure, casting section and test-coupon scope matter more than a familiar class number.
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).