Grey Iron Castings & Grey Iron Casting Companies

Grey iron castings are alloyed iron components manufactured by melting and molding molten metal at specific rates and temperatures so as to create parts and components of variable grades and qualities as needed for industrial applications. Also spelled gray iron, these castings have been used throughout history due to the abundance and low cost of iron.

A type of cast iron, the name of grey iron is derived not only from the basic elemental composition of the material, but also from the coloring of fractured surfaces of the metal. This method is commonly used to distinguish between iron alloys though the molecular structure is also very different. Even within the category of grey casting there are several different types, such as ductile castings and spheroidal graphite cast iron, based on molecular composition and internal structure. Even minor differences lead to considerable variation of the many desirable features of grey iron such as low melting point, resistance to deformation and wear, energy dissipation and thermal conductivity. As casting and machining can also alter these qualities, specific iron castings must be carefully compared to their intended use to ensure structural competence. Because so many variations exist, iron foundries often offer several different metallurgical and core processes to produce plain gray iron castings as well as ductile iron castings. One of the most popular operations is green sand casting, though die casting is also extremely popular within the industry. The selected casting method depends largely upon the desired size and characteristics needed for the finished part. Foundry professionals may provide additional insight into the most appropriate use of grey iron castings.

Some Leading Manufacturers

MES, Inc.

Lewis Center, OH | 740-201-8112

MES, Inc. is a reliable source for a broad range of cast iron products. We serve customers around the world with high quality iron castings and exceptional manufacturing services. We cast many different types of iron, including standard iron, gray iron, ductile iron, and white iron. We can handle even your most unique requirements! With machining, engineering, painting, anodizing, and assembly services, we can take on your whole project! Contact us today!

Imperial Casting Company, Inc.

Florence, AL | 256-766-8720

Imperial Casting Company has been manufacturing high quality gray iron castings for more than 46 years. We specialize in creating high strength iron castings from customers’ tooling and new tooling from blueprints or samples. We provide sand casting, green sand casting, airset sand casting, no-bake sand casting, and a multitude of secondary operations as well. Contact us to discuss your needs or visit our website to send a request for quote!

West Salisbury Foundry and Machine Company

West Salisbury, PA | 814-662-2809

As the premier manufacturer of iron castings, West Salisbury Foundry and Machine Company is your source for gray iron castings of all kinds. We have been serving industrial companies around the nation for more than a century, so you can count on us to get the job done right every time. Using our extensive experience, highly skilled staff, and state-of-the-art equipment, we can supply you with engineered castings to your specifications. Connect with us today to find a solution for your casting needs.

Pacific Alloy Castings Co., Inc.

South Gate, CA | 562-928-1387

As an ISO 9001:2008 certified company, Pacific Alloy Castings Co. is your source for reliable, high quality iron castings. We specialize in casting components for the construction, mining, agriculture, asphalt mixing and paving, and aggregate processing industries. We have been in the casting industry for more than 75 years, and with our extensive experience and expertise, we can create a cast iron product for your applications. Check out our website or call us today for more information!

State Line Foundries

Roscoe, IL | 815-389-3921

Here at State Line Foundries, we have more than 45 years of experience manufacturing and supplying precision iron castings. Whether you need gray or ductile iron, we have you covered! We focus on versatility, so that regardless of your requirements we can adapt to serve you with the very best metal casting solution. We will continually work with you to design and create the perfect and most economical casting for the job! Give us a call today!

Warsaw Foundry Company, Inc.

Warsaw, IN | 574-267-8772

As a world-class manufacturer and supplier of gray iron castings, Warsaw Foundry Company is your reliable source for high quality cast iron products. We have served the casting industry for more than 90 years, and we cast products ranging from just one ounce to 150 pounds. We also support your prototyping and full product requirements. With a focus on customer service, competitive pricing, and on-time delivery, we are the right source for your cast iron product needs!


Making up 5% of the Earth’s crust and 35% of its total mass, iron is the most copious element on the planet. Rarely found in pure form, however, iron oxides or iron ores must be mined and processed to produce grey iron. Metalworkers achieve this through the use of a special type of blast furnace known as a cupola or an electric induction furnace. Though several standardized grading systems are available, the general composition of grey cast iron is 95% iron by weight with an additional 2.1 to 4% being carbon and 1 to 3% silicon. Manganese and other impurities are also commonly found in or added to molten iron as needed for the diminishing or enhancement of specific properties. Sulfur, for example, is commonly introduced to the molten metal in order to increase hardness which is otherwise low in most cast iron components. Specific to grey cast iron is a high amount of silicone which is responsible for the production of graphite when the alloyed materials are heated. The deflection of this graphitic microstructure is what gives the metal its grey appearance. Though most often in flake form, ductile cast iron production slows down the growth of graphite and allows the carbon to separate as spheroidal graphite particles instead. Both the timing and temperature play important roles in the structural disposition of grey iron castings.

With desirable stock material readied, iron foundries use several different processes to produce grey iron castings. Virtually every technique requires the liquification of the grey iron which is then poured into a mold and cooled at precise rates before the completed part is ejected. Die casting employs reusable dies which contain an impression of the finished product. This method is popular when continuous cycle or fast production is needed. Centrifugal casting is used for cylindrical parts and components and works by rotating the mold at high speeds as the molten metal is introduced. This creates a fine grained outer surface with even dispersion. Sand molding is another commonly used process as it is low cost and easily accomplished. A two part mold cavity is formed using a sandy mixture, the composition of which can be any of four choices which include green sand, skin-dried, dry sand and no bake. The material chosen depends largely upon the accuracy needed and the desired surface finish which is often rough and may require finishing operations. As most mold and casting techniques leave the possibility for burrs and other undesirable artifacts, iron foundries often provide a number of secondary operations in order to provide more finished products. Additionally, processes such as annealing, machining, painting and galvanizing among others may also be had at several metallurgical work shops.

Though often confused with forges, only foundries provide the closed mold operations needed to produce quality grey iron castings for the many industries that employ them. Automotive, agricultural, machinery building, electronics, irrigation, ventilation, architecture, construction and transportation industries all utilize these molded parts in daily operations as they provide both strength and durability. As a building and construction component, grey iron castings provide protection against fires as they are non-flammable and thus preferred over wooden support structures. The graphite content of the parts also provides reliable and efficient energy dissipation making the parts suitable for applications in which the dampening of mechanical vibrations is required or desired such as crankshafts and engine blocks. Additional cast grey iron components commonly used include pipes, cases, dies and even decorative embellishments as the material is easily machined with accuracy and precision.

Plymouth Foundry, Inc.

Green Sand Iron CastingsGrey Iron Castings – Plymouth Foundry, Inc.