Gray and Ductile Iron Castings for Engineering Applications

Gray and ductile iron castings are specified for a wide range of engineering objectives. Gray iron is selected for ease of machining, high compressive strength, and excellent vibration absorption, while ductile iron has higher tensile strength and toughness similiar to steel.

Ductile iron castings are good substitutes for steel weldments.

Some typical applications for our gray and ductile iron castings include:

• Machinery bases, housings, and brackets.
• Pump bases, brackets, and housings.
• Gear, cam, and follower blanks.

Gray Iron Castings

At OK Foundry every furnace heat is measured for carbon content by thermal analysis and the carbon content is adjusted to meet target levels. By carefully adjusting carbon content, OK Foundry casts a wide range of gray iron as specified by ASTM A48, Standard Specification for Gray Iron Castings .

Since gray iron tensile strength and machinability is also controlled by the casting section thickness, the ability to adjust chemistry in small furnace heats is the key to short leadtime casting of small and large castings. We can melt several chemistry programs in a single day with our fast melt induction furnaces, shortening leadtimes for all our castings.

Gray iron has been described as "steel plus graphite" by E. B. Krouse in Gray Iron-A Unique Engineering Material. This informative white paper goes on to say that "carbon is by far the most important element in gray iron."

Find out everything you need to know about Gray Iron by reading Gray Iron-A Unique Engineering Material.

Ductile Iron Castings

Over forty years ago, the birth of a new engineering material, Ductile Iron, was announced at the 1948 American Foundrymen's Society Annual Conference (reference: Introduction, Ductile Iron Data, Ductile Iron Society). With mechanical properties similar to steel and castability and machinability similar to gray iron, ductile iron has continued to grow in use as an engineering material and as a cost effective replacement for steel components (reference: Designing with Ductile Iron, Ductile Iron News, Issue 1, 2001).

OK Foundry has decades of experience with ductile iron and our flexible casting program makes introduction of new parts quick and efficient. A ductile iron casting can significantly reduce machining costs by replacing machining with as cast features and increasing machine speeds and feeds. Ductile Iron Data for Design Engineers from the Ductile Iron Society provides a complete description of the design advantages of ductile iron.