1. Product Overview
Large cast steel girth gears are the core transmission components used in heavy industrial machinery such as rotary kilns, ball mills, dryers, and vertical mills.
They play a vital role in industries like mining, cement, metallurgy, and power generation, where reliability and strength are critical.
As global manufacturing continues to upgrade, girth gears are evolving toward larger sizes, higher precision, and stronger mechanical performance.
Today, single-piece diameters can exceed 10 meters, meeting the demanding requirements of modern heavy-duty operations.
2. Manufacturing Process
At Hanhai Casting, every production stage is strictly controlled to meet international metallurgical and mechanical standards.
2.1 Smelting & Pouring
High-purity alloy steel is melted in medium-frequency induction furnaces and vacuum-degassed to ensure chemical uniformity and purity.
2.2 Heat Treatment & Quenching
Optimized heat treatment refines grain structure, enhances toughness, and increases the fatigue strength and surface hardness of the gear ring.
2.3 Machining & Gear Hobbing
Precision CNC machining guarantees excellent tooth geometry, achieving Grade 8 accuracy or better and over 98% transmission efficiency.
2.4 Testing & Quality Control
Each casting undergoes ultrasonic (UT), magnetic particle (MT), and radiographic (RT) inspection to eliminate cracks, porosity, and inclusions.
3. Key Features and Advantages
- ⚙️ High-strength alloy steel casting ensures superior load-bearing capacity.
- 🔧 Precision gear machining delivers smooth operation with minimal vibration and noise.
- 🔥 Excellent wear and heat resistance, ideal for high-temperature, heavy-load environments.
- 🧩 Customizable designs available for different tooth modules and gear diameters.
- 🌍 International standard compliance — ASTM, DIN, GB, and ISO certified.
4. Application Fields
Hanhai Casting’s large cast steel girth gears are widely used in:
- 🪨 Mining industry: crushing systems, grinding mills, and conveying equipment.
- 🏗️ Building materials industry: rotary kilns, vertical mills, and drying systems.
- 🔩 Metallurgical plants: steel rolling and pelletizing kilns.
- ⚡ Power generation: coal mills and fan drive systems.
- 🧪 Chemical industry: rotary reactors and processing drums.
Our products are exported to the Middle East, Southeast Asia, Central Asia, Africa, and South America, where they are highly recognized by industrial clients.
5. Customization & Quality Assurance
Hanhai Casting operates a fully traceable in-house production system — from pattern design and casting to machining, heat treatment, and final assembly.
We are equipped with advanced testing and inspection tools, including:
- Optical emission spectrometers
- Metallographic microscopes
- Coordinate measuring machines (CMM)
- Ultrasonic and magnetic particle testing systems
This ensures that every girth gear meets global standards for strength, durability, and dimensional precision.
6. Global Cooperation & Outlook
Hanhai Casting aims to become a global leader in high-quality cast steel components.
With cutting-edge production technology, rigorous quality management, and professional international service, we provide long-term solutions for heavy-equipment manufacturers worldwide.
Our Cooperation Scope Includes:
- OEM & ODM production
- Spare-part supply contracts
- On-site installation support
- Technical consulting and after-sales service
📞 Contact Us:
For quotations, technical data, or custom design support, please visit www.hanhaicasting.com
or email service1@hanhaicasting.com.







