Cast Iron•Gray Cast Iron•

VERIFIED(Source-Verified)

EN-GJL-300 Gray Cast Iron

Primary Designation:EN EN-GJL-300

Aliases:

GG-30EN-JL1050Grey Iron 300

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Data Completeness:6 composition elements and 9 condition-specific property values cataloged.

Omitted fields represent unverified properties. "Missing is better than invented."

Key Engineering Properties

Representative source rows, qualified by their reported conditions. Inspect the tables below for all values, limits, and source notes.

Density

7.25 g/cm³TYPICAL · temperature not stated

Thermal Conductivity

43 W/(m·K)TYPICAL · temperature not stated

Specific Heat Capacity

490 J/(kg·K)TYPICAL · temperature not stated

Composition Excerpt

C 2.9–3.25 wt%Carbon (range)

Standard Elemental Basis: RANGE

Engineering Summary

EN-GJL-300 (material number EN-JL1050 / former DIN GG-30) is a high-duty, wear-resistant European gray cast iron. Specified in EN 1561 with a minimum tensile strength of 300 MPa on 15 mm to 30 mm wall sections, it has a dense, finely lamellar pearlitic matrix and high compressive resistance (~900 MPa), tailored for highly loaded gears, diesel engine cylinder blocks, and heavy press structures.

EN-GJL-300 Gray Cast Iron Documented Applications

›Heavy diesel engine cylinder blocks, heads, and liners
›Industrial gears, transmission housings, and clutch housings
›High-pressure compressor cylinders and hydraulic control blocks
›Heavy machine tool frames requiring maximum stiffness and damping

Recognized Aliases

Source-backed commercial trade name and short designations cataloged in canonical data.

GG-30EN-JL1050Grey Iron 300

EN-GJL-300 Gray Cast Iron Specifications & Designations

Standard Designations & Applicable Specifications — Semantically classified designations distinguishing primary standard identifiers, commercial trade names, and applicable specification references.

Direct Standard DesignationsDIRECT DESIGNATION

4 Primary Identifiers

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System	Identifier	Standard System Name	Classification Notes & Provenance
ENPRIMARY	EN-GJL-300	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-JL1050	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	GG-30	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	185/JL/300	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 Commercial Aliases & Trade NamesCOMMON ALIAS

3 Listed

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Recognized Name / Alias	Classification	Technical Usage & Context
GG-30	Historical Alias	Colloquial or commercial industry synonym
EN-JL1050	Commercial Alias	Colloquial or commercial industry synonym
Grey Iron 300	Colloquial Alias	Colloquial or commercial industry synonym

Applicable Specifications & Product Form ReferencesSPECIFICATION REFERENCE

2 Applicable Standards

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Standards Body	Specification Code	Specification Title / Scope	Relationship Type
CEN	EN 1561	Founding — Grey cast irons	Specification Reference
ISO	ISO 185	Grey cast irons — Classification	Specification Reference

Engineering Notice: Applicable specifications establish manufacturing requirements, dimensional tolerances, and test criteria for specific product forms (e.g. bus bar, wire, plate, pipe). They represent applicable technical standards, not alternative or equivalent alloy grades.

EN-GJL-300 Gray Cast Iron Chemical Composition

Chemical Composition (Weight %) — Elemental limits and values from the cited source. Preserves exact semantic limits (minimums, maximums, and ranges).

Scroll horizontally for full elemental limits

Element	Symbol	Semantic Basis	Specified Value	Unit	Metallurgical Notes & Qualification	Data Status
Carbon	C	RANGE	2.90 – 3.25	wt%	Ref: ASTM International, CEN, ISO & ASM International Standards Technical Committees	VERIFIED
Silicon	Si	RANGE	1.60 – 2.00	wt%	Ref: ASTM International, CEN, ISO & ASM International Standards Technical Committees	VERIFIED
Manganese	Mn	RANGE	0.70 – 1.05	wt%	Ref: ASTM International, CEN, ISO & ASM International Standards Technical Committees	VERIFIED
Phosphorus	P	MAXIMUM	≤ 0.10	wt%	Ref: ASTM International, CEN, ISO & ASM International Standards Technical Committees	VERIFIED
Sulfur	S	MAXIMUM	≤ 0.12	wt%	Ref: ASTM International, CEN, ISO & ASM International Standards Technical Committees	VERIFIED
Iron	Fe	REMAINDER	Remainder	wt%	Ref: ASTM International, CEN, ISO & ASM International Standards Technical Committees	VERIFIED

* Elemental percentages are expressed in weight percent (wt%). Values represent applicable specification limits. Unspecified trace elements are not fabricated or assumed.Preserves exact semantic basis

Property Display UnitsSwitch between Canonical SI and Source / US Customary units:

EN-GJL-300 Gray Cast Iron Physical Properties

Source-specific physical properties. Test temperatures are shown only where reported.

1 Parameters

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Property Parameter	Canonical SI Value	Semantic Basis	Test Temperature / Context Range	Source Raw Reference	Source Reference	Status
Density	7.25 g/cm³	TYPICAL		7.25 g/cm³	ASTM International, CEN & ISO Technical Committees	VERIFIED

EN-GJL-300 Gray Cast Iron Thermal & Thermodynamic Properties

Phase change temperatures, thermal conductivity, specific heat, mean coefficients of thermal expansion across standardized temperature ranges, and recommended thermal processing windows.

3 Parameters

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Property Parameter	Canonical SI Value	Semantic Basis	Source Raw Reference	Source Reference	Status
Thermal Conductivity	43 W/(m·K)	TYPICAL	43 W/(m·K)	ASTM International, CEN & ISO Technical Committees	VERIFIED
Specific Heat Capacity	490 J/(kg·K)	TYPICAL	490 J/(kg·K)	ASTM International, CEN & ISO Technical Committees	VERIFIED
Coefficient of Thermal Expansion	10.8 µm/(m·K)	TYPICAL	10.8 µm/(m·K)	ASTM International, CEN & ISO Technical Committees	VERIFIED

EN-GJL-300 Gray Cast Iron Electrical Properties

Electrical conductivity and resistivity in their reported units and conditions.

1 Parameters

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Property Parameter	Canonical SI Value	Semantic Basis	Test Temperature / Context Range	Source Raw Reference	Source Reference	Status
Electrical Resistivity	620 nΩ·m	TYPICAL		620 nΩ·m	ASTM International, CEN & ISO Technical Committees	VERIFIED

EN-GJL-300 Gray Cast Iron Mechanical Properties

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.

Elastic & Baseline Mechanical ConstantsSource-specific measurement conditions

Poisson Ratio

0.27 dimensionless

Showing 3 of 3 conditions

Scroll horizontally for all conditions & tempers

Product Form	Temper / Condition	Section Size	Tensile (UTS)	Yield Strength	Elongation	Shear Strength	Fatigue Strength	Hardness (Scales Preserved)	Status
Standard Product Form	As-Cast Source values and qualifiers Ultimate Tensile Strength: ≥ 300 MPa (MINIMUM)Governing minimum tensile strength per EN 1561 for 15–30 mm wall thickness.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	— · 15 mm to 30 mm wall thickness	≥ 300 MPa	—	—	—	—	—	VERIFIED
Standard Product Form	As-Cast Source values and qualifiers Modulus of Elasticity: 115 GPa (TYPICAL)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	—	—	—	—	—	—	—	VERIFIED
Standard Product Form	As-Cast Source values and qualifiers HBW Hardness: 200–255 HBW (RANGE)10/3000ASTM 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	—	—	—	—	—	—	200–255 HBW	VERIFIED

Hardness Integrity Notice: Rockwell B (HRB), Rockwell F (HRF), and Superficial 30T (HR30T) scales are reported on their measured scales without cross-scale mathematical conversion.

Source: See fact-level citations

EN-GJL-300 Gray Cast Iron Processing & Fabrication

Machining, joining, forming, and thermal processing ratings cataloged from the cited authoritative technical reference.

Source: ASTM International, CEN, ISO & ASM International Standards Technical Committees

Machinability

Moderate machinability (~75% of C36000 baseline). Fine pearlitic matrix and high hardness require sturdy tooling.

Weldability & Joining

Poor weldability. Welding is strictly discouraged except for qualified minor repair using 300°C preheat.

Heat Treatment & Working Ranges

Stress relief at 560°C–600°C.

Forming & Cold Working

Non-deformable.

EN-GJL-300 Gray Cast Iron Equivalent & Comparable Grades

Comparable Grades & Cross-References: Carefully classified cross-reference relationships for EN-GJL-300 Gray Cast Iron. Comparable does not mean equivalent.

Scroll horizontally for relationship classifications & comparisons

Related Material	Family	Relationship Classification	Metallurgical Notes & Differences	Status	Action
ASTM A48 Class 40 Gray Cast Iron	Cast Iron	Commonly Compared	EN-GJL-300 provides higher tensile strength (300 MPa) than Class 40 (276 MPa), serving severe load cases in European engineering designs.Materials serve different design priorities (e.g. higher strength vs superior corrosion resistance or cost).	VERIFIED	Side-by-Side Compare →

Related Engineering & Metallurgy Guides

Contextual technical guides explaining degradation mechanisms, testing methodologies, and selection criteria relevant to EN-GJL-300 Gray Cast Iron.

Corrosion & Surface Engineering15 min read

How to Remove Rust From Cast Iron: Methods, Science & Prevention

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.

Author: MatGrades Materials Engineering GroupRead Guide →

Sources

Sources & Provenance Trail: Authoritative reference publications, standards specifications, and data registers cited across this material record.

ASTM International, CEN & ISO Technical CommitteesStandard 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)

STANDARDS ORG

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).

Issuing Body: ASTM International, CEN, ISO & ASM International Standards Technical CommitteesRevision: ASTM A48/A48M-22 / ASTM A536-84(2024) / EN 1561:2020 / EN 1563:2018 / ISO 185:2020 / ISO 1083:2018View Source Record ↗

Intellectual Property & Provenance Notice: Mat Grades cites technical literature from recognized industry associations and standards organizations. Underlying technical standards and publication data remain the intellectual property of their respective issuing organizations.