gray iron foundry

High-Quality Gray Iron Casting Foundry

Casting Highlights

Are you in need of high-quality gray iron castings for your industrial applications? Look no further! As a leading gray iron casting foundry in China, we offer a comprehensive range of gray iron products to meet your specific requirements. With our expertise and commitment to excellence, we are your one-stop solution for reliable and durable gray iron castings.

Superior Strength and Durability
Superior Strength and Durability

Our gray iron castings are manufactured to meet ASTM A48 standards, ensuring exceptional tensile strength and long-lasting performance.

Excellent Thermal Conductivity
Excellent Thermal Conductivity

Gray iron is renowned for its high thermal conductivity, allowing for efficient heat transfer and improved operational efficiency in various applications.

Optimal Machinability
Optimal Machinability

With good machinability, our gray iron castings can be easily shaped and finished to precise specifications, saving you time and effort in post-production processes.

Outstanding Damping Capacity
Outstanding Damping Capacity

Gray iron exhibits excellent damping properties, effectively reducing vibrations and noise in machinery and equipment, resulting in smoother operation.

Versatile Applications
Wide Range of Applications

Our gray iron castings find applications in diverse industries, including automotive, agricultural machinery, mining, and construction, among others. From frames and gearboxes to cable drums and pumps, our castings deliver reliable performance in demanding environments.

5 Products Found.

OEM Equivalent Quality


Customized Solutions Tailored to Your Needs

As a customer-centric company, we understand the importance of providing tailored solutions. We work closely with our clients to understand their specific requirements and deliver customized gray iron castings that meet their unique needs. With our expertise in casting, forging, and CNC machining, we can provide comprehensive solutions for your mining, construction, and rail applications.

Soluciones personalizadas para cuchillas para niveladoras
Strict Quality Control for Reliable Performance

Strict Quality Control for Reliable Performance

Quality is at the core of everything we do. Our gray iron castings undergo rigorous quality control measures to ensure they meet the highest standards of performance and durability. By adhering to international quality certifications, such as ISO9001 and TS16949, we demonstrate our commitment to delivering products of exceptional quality and reliability.

Competitive Pricing and Timely Delivery

We understand the importance of cost-effectiveness and timely delivery in today’s competitive market. With our efficient manufacturing processes and streamlined operations, we offer competitive pricing without compromising on quality. Additionally, our well-established supply chain and logistics capabilities enable us to deliver your gray iron castings promptly, ensuring minimal downtime for your operations.

Precios competitivos y el mejor servicio

Models That We Can Assemble

Production System

Casting Types

Testing Equipment


What is the Lead Time?

Casting:30-60 days.

CNC machining:15-30 days.

What is the Payment Methods?

Our payment options include T/T, L/C, or O/A.

What is the Warranty?

One year without vandalism.

Causes and Prevention of Fine Cracks in Gray Iron Castings

Upon examining many materials, it’s apparent that the appearance of cracks in gray iron castings can be attributed to a variety of factors, including but not limited to flawed casting process, metal composition, high-stress production conditions, and poor machining practice. To prevent such issues, you must understand these causes fully and employ meticulous inspection of each step in the casting process.
At NingBo Winner Tiger Machinery Co., Ltd, established in 2012, we specialize in supplying casting, and CNC machining spare parts for various industries, including mining and construction. With our custom specifications, product quality checks, and assurance of delivering as per global standards such as DIN, ASTM, GOST, ISO, and BS, we ensure high-quality production delivery.
In the case of gray iron castings, several common reasons contribute to the development of fine cracks, which include:
Poor Molding Conditions: If the molding process isn’t handled efficiently, the possibility of cracks appearing increases. Therefore, maintaining the proper molding environment is necessary to ensure the integrity of the casting.
Increased Casting Stress: Failing to provide sufficient allowance for the core during metal shrinkage could result in higher casting stress, potentially leading to fine cracks. Therefore, the allowances should be meticulously observed to decrease the casting stress levels.
Inadequate Machining Practice: If machining isn’t carried out correctly, it can lead to uneven stress distribution throughout the casting, eventually leading to cracks.
Understanding these potential pitfalls, our process at NingBo Winner Tiger Machinery Co., Ltd, is designed to mitigate these risks. Our casting services boast of a casting tolerance of CT5–CT15, with dimensions up to 1500mm and a unit weight ranging from 0.1kg to 2500kg.
To prevent these casting defects, including fine cracks, it is imperative to ensure a good casting process. Some preventive measures include:
Enhanced Casting Process: Adopting efficient casting methods such as investment casting, sand casting, and precision casting can improve the molding environment and thus reduce casting defects like fine cracks.
Improved Machining: Turn, cut, mill, grind, drill– every step must ensure that the casting is processed efficiently and accurately. This helps in the stress distribution, reducing the chances of crack formation.
Quality Control: Maintain a rigorous quality control system. We adhere to FEMA, PPAP, APQP, Control Plan, and MSA. Not just that, we also ensure that all requirements’ certificates and test reports are delivered with every dispatch.
The journey to perfect casting without defects can seem daunting, but with years of experience and continuous improvements, NingBo Winner Tiger Machinery Co., Ltd. has made strides in product quality and customer service. Whether you’re involved in automobile, agriculture, mining, or construction, we’re always here to provide high-quality, competitively priced casting components. Don’t hesitate to get in touch!

An Overview of Grey Iron Casting

Grey iron or sometimes referred to as grey cast iron is a variety of cast iron that contains large amounts of graphite, which gives it a grey color. One of the most widely used cast iron, it is commonly used in internal engine parts, valves, and cooking utensils, among many others.
Q1: What is Grey Iron?Grey iron, as the name suggests, is a type of cast iron that has a grey color due to the presence of graphite flakes in its structure. The dimensions and form of these graphite flakes play a significant role in the strength of grey cast iron.
Q2: What are the advantages of Grey Iron?Grey iron is preferred for various reasons:
Lower manufacturing cost – It’s highly suitable for mass production.
Superior yield strength – Despite having lower tensile strength, its applications outweigh other cast irons due to its high yield strength.
Good machinability – Grey iron can be easily machined, which makes it ideal for various applications.
Exceptional damping capacity – It can absorb energy and convert it into heat, making it highly desirable for use in many machines and housings.
Easy to weld – Due to its low resistivity and ductile strength, grey iron can be welded relatively easily.
Excellent thermal cycling endurance – It doesn’t become hot or cold too quickly.
Q3: What are the applications of Grey Iron?Due to its high resistivity to heat and strength, grey cast iron is commonly used to manufacture manhole covers on streets and brakes in vehicles. Its thermal cycling endurance makes it ideal for manufacturing cooking utensils.
Q4: How is Grey Iron different from other types of cast iron?Compared to other types of cast iron, grey cast iron has a relatively higher phosphorous content. Additionally, it features interwoven graphite flakes that give it a unique structure and properties.
At NingBo Winner Tiger Machinery Co., Ltd, we have a wide array of cast iron options to suit your unique needs, including grey cast iron. With our expertise and commitment to quality, we guarantee you high-quality grey iron casting suited to your specific requirements. Contact us today for more information!

03How Does Heat Treatment Improve the Quality of Our Products

By understanding the important role of heat treatment in metal casting, it’s clear why NingBo Winner Tiger Machinery Co. always aims for quality. Our company provides quality casting, forging, and CNC machining spare parts, but at the heart of it all is the science of heat treatment that guarantees the properties of our steel castings.
Come On a Journey with Us
When you think about metal casting, you probably think about the pouring, molding, shaking out, and cleaning process. But have you ever considered how heat plays such a crucial role in metal casting? Heat treatment, which involves the application of heat and cooling at different rates, is an essential step in assuring the mechanical properties of steel castings.
Just like the crystalline structures that form when molten metal cools, the distinctive grain of a metal helps to create its mechanical properties. The size and relationship of the grains in the alloy can make all the difference in how the metal holds up under pressure. Heat treatment enables us to reshape these grains, and thus change the properties of the metal.
The Science Behind the Strength
At NingBo Winner Tiger Machinery Co., we optimize these properties by choosing the right alloy and using specific heat treatment methods for each product. Annealing, normalizing, quenching, and tempering are all processes at our disposal that we fine-tune for specific products and applications.
Annealing involves heating the steel and letting it cool in the furnace at a very controlled rate. This process helps to increase the ductility, tensile strength, and elongation of the metal, resulting in a highly malleable product.
Normalizing, on the other hand, involves heating the steel and then allowing it to cool in the atmosphere. This leads to a product with many of the same properties as annealed metals but with a slightly different grain structure, making it typically stronger or harder.
For parts where a very high degree of hardness is required, like tools or machine parts, we use quenching to achieve this. Quenching involves soaking the steel until it reaches a certain molecular structure, then cooling it rapidly in oil or forced air. This rapid cooling results in a structure that is harder due to carbon distortion in each molecule.
To find the ideal balance of hardness and ductility, we use tempering. This process involves reheating the metal to a lower temperature, causing the hard martensite structure to start converting to softer structures. This process can make the metal less brittle while preserving some of the hardness.
Why It Matters
Through heat treatment, we at NingBo Winner Tiger Machinery Co. are able to produce metal parts that meet specific requirements, whether it’s high strength for mining or construction equipment or ductility for railway components. The process ensures that all our products, regardless of their use, have the best chance of standing up to the toughest conditions.
We’re always happy to answer any questions about our heat treatment process and how it improves the quality of our products. We believe in high quality, competitive prices, and exceptional service, so feel free to contact us anytime.

Inspection Methods for Large Ductile Iron Castings Ensuring Quality and Reliability

At NingBo Winner Tiger Machinery Co., Ltd, we understand that the quality of our products lies in each and every detail. For our large ductile iron castings, we employ a meticulous inspection process to ensure our items meet the highest quality standards. We would like to provide a brief rundown of our tried and tested inspection procedures:
1. Visual Inspection:
The first step in our process is visual inspection. Our primary aim here is to detect any obvious flaws or imperfections, such as cracks, slag inclusions, or other visible defects. An important aspect of visual inspection is ascertaining that there are no welding treatments, no cracks, no slag inclusions or sand, and no air or sand holes. We also ensure that there are no defects or cold flake, and no impressions or scratches due to machining. In addition, we double-check sandblasting quality, ensuring adequate surface quality and absence of the oxide skin.
It’s worth noting that we carry out detailed checks on specific casting aspects, such as the casting head areas that can easily contain defects or flaws. If visual inspection reveals any form of flaw or irregularity, we employ measures such as re-sanding or regrinding to enhance the quality and uniformity.
2. Magnetic Particle (Powder) Inspection:
Magnetic Particle Inspection, also known as Magnetic Powder Inspection, is an accomplished method of non-destructive testing (NDT). This method is greatly recommended for ductile iron castings. It enables us to identify any potential detrimental flaws beneath the surface, which might not be visible through naked eyes.
3. Ultrasonic Testing:
Ultrasonic testing not only enables us to detect sand holes and air holes, but it also allows for the inspection of cracks, slag inclusion, and various material defects. Such testing demands a certain level of expertise, however, as ductile iron features a complex internal structure that can lead to false judgment. But at NingBo Winner Tiger Machinery Co., our skilled and experienced testing teams are capable of executing these tests with optimum preciseness.
Understanding the importance of each stage in the inspection process is key to ensuring the quality of the final ductile iron casting product. Rest assured, our team is always eager to answer any queries you might have about our processes. Feel free to contact us anytime, and we will be more than happy to assist you.
For more knowledge about the inspection methods for large ductile iron castings, you may read more about it here.

Factors Affecting the Hardness of Grey Iron Castings

Grey iron castings, also known as grey cast iron, is well known for its excellent casting performance, high wear resistance, and good machinability. However, one common issue often encountered by manufacturers is the hardness of the castings. Let’s dive into the potential causes and solutions:
1. Chemical Composition:
The chemical composition of iron greatly influences its hardness. Specifically, the manganese content plays a crucial role. When the manganese content is high, it results in higher hardness in the grey iron castings, making surface machining challenging.
2. Casting Thickness and Cooling Speed:
Thin castings cool quickly, leading to the occurrence of white mouth problems. This changes the iron from grey iron to white iron, which has a much harder structure, causing difficulties during machining.
3. Tool Selection:
Grey iron castings naturally have a relatively high hardness, so the selection of cutting tools is crucial. Proper tool selection can help alleviate the issue, for example using a G8 cutter for rough machining, a G6 for semi-finishing, and a G3 for fine finishing. For exceptionally hard castings, cubic boron nitride (CBN) cutting tools that can machine at up to 60 HRC are recommended.
Additionally, it’s important to pick correct turning speed and feed rate for machining processes.
4. Heat Treatment:
Subsequent heat treatment such as annealing can reduce the hardness of iron castings and also eliminate the internal stresses caused during casting, making the parts easier to machine.
At NingBo Winner Tiger Machinery Co., Ltd, we manage these factors optimally and ensure high quality control standards so that we deliver the best-in-class grey iron castings to you.
For more information about factors affecting the hardness of grey iron castings, you can read it here.
Feel free to reach out to us if you have more queries regarding our casting processes or if you need more understanding about grey iron castings. We’re always happy to help!

The Correlation between Hardness and Grey Iron Castings

Grey iron castings, also referred to as grey cast iron, are recognized for their remarkable castability, top-notch wear resistance, and great machinability. However, one significant concern that manufacturers face is the casting’s hardness. This article aims to unravel the factors influencing hardness and offer some solution strategies.
1. The Role of Chemical Composition:
The chemical composition, particularly the manganese content, has a significant bearing on the grey iron casting’s hardness. A high concentration of manganese escalates the hardness of the casting, rendering machining of the surface challenging.
2. Casting Thickness and Cooling Speed:
The thickness of the casting and the speed at which it cools down also dictates hardness. With thin castings, faster cooling can trigger the development of issues like ‘white mouth’. This alters the casting from grey iron to white iron, which is significantly harder and more difficult to machine.
3. Insights on Tool Selection:
Because grey iron castings inherently have high hardness, the choice of cutting tools becomes crucial. For instance, a G8 cutter can be employed for rough machining, G6 for semi-finishing, and G3 for fine finishing. For particularly hard castings, cubic boron nitride (CBN) cutting tools are recommended – these can machine at hardness up to HRC 60. It is equally important to select the correct turning speed and feed rate for machining.
4. Heat Treatment:
Applying subsequent heat treatment operations like annealing can help decrease the hardness of the iron castings, making them easier to machine. It also eliminates the internal stresses caused during casting.
At NingBo Winner Tiger Machinery Co., Ltd, we optimally manage these factors to ensure high standards of quality control, thereby delivering best-in-class grey iron castings. We are always prepared to answer any questions you might have concerning our casting procedures. Feel free to contact us anytime for assistance.

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