Gray Cast Iron – Properties, Casting Expertise & Applications
Introduction to Gray Cast Iron
Gray Cast Iron is one of the oldest and most reliable engineering alloys, recognized for its graphite flake microstructure that gives a unique gray fracture surface. This structure provides a combination of vibration damping, heat conductivity, and wear resistance unmatched by many other cast metals.
At TX Metal, we approach Gray Iron not only as a material but as an engineering solution. With decades of experience in metallurgy and precision casting, we help industries design and manufacture durable components that balance performance and cost.
Why Engineers Choose Gray Cast Iron From TXmetal
Gray Cast Iron offers a balance of performance, reliability, and economy that makes it one of the most widely selected casting materials in modern engineering.
- Superior Damping Capacity – Ideal for machinery bases and housings that must absorb vibration and noise.
- Thermal Management – Excellent heat dissipation makes it a preferred material for brake discs, engine parts, and heat-exposed housings.
- Cost-Effectiveness – Lower melting temperature and casting ease reduce energy consumption and tooling cost.
- Machinability Advantage – Graphite flakes improve chip breaking and extend tool life in CNC operations.
- Dimensional Stability – Low shrinkage during solidification ensures accurate, repeatable castings.
Gray Iron Grades and Standards
TX Metal supplies Gray Cast Iron according to major international standards, ensuring compatibility with your design specifications:
- China (GB/T 9439): HT200, HT250, HT300
- USA (ASTM A48): Class 30, 35, 40, 50
- Europe (EN-GJL): EN-GJL-200, EN-GJL-250, EN-GJL-300
- Japan (JIS G5501): FC200, FC250, FC300
Each grade differs in tensile strength, hardness, and microstructure balance. Our metallurgical team assists in grade selection based on functional and cost requirements.
Mechanical Properties (Typical Range)
| Grade (ASTM) | Tensile Strength (MPa) | Hardness (HB) | Key Benefits |
|---|---|---|---|
| Class 30 | 200–250 | 150–190 | High machinability, damping |
| Class 40 | 250–300 | 170–210 | Balanced strength and castability |
| Class 50 | 300–350 | 190–240 | Enhanced strength, wear resistance |
TX Metal’s Casting and Engineering Capabilities
With a fully integrated foundry and machining facility, TX Metal provides end-to-end solutions that ensure every Gray Cast Iron casting meets both performance and production requirements.
- Casting Methods: Green sand, resin sand, and shell molding for weights from 1 kg to 1000 kg
- Process Control: Advanced melting furnaces, spectrometer analysis, thermal analysis for consistent metallurgy
- Quality Assurance: Tensile testing, hardness checks, ultrasonic & dimensional inspection
- CNC Machining Integration: Turning, milling, drilling, and surface finishing for ready-to-install components
- Engineering Support: Simulation software to predict solidification, reduce defects, and optimize designs
Get a Free Quote from Our Iron Foundry
Send your drawings or samples, and we’ll provide a custom proposal. We evaluate material specifications, casting weight, machining requirements, and lead times to deliver the best solution for your project.