SG Iron

SG Iron Casting

SG Iron is also known as Spheroidal Graphite Iron, Ductile Cast Iron, Nodular Cast Iron, and Spherulitic Graphite Cast Iron. SG Iron is a type of cast iron that has been treated while molten with an element such as magnesium or cerium to induce the formation of free graphite as nodules or spherulites. This imparts a measurable degree of ductility (easily manipulated) to the cast metal. The ductile iron family offers the design engineer a unique combination of strength, wear resistance, fatigue resistance, and toughness, as well as excellent ductility characteristics.

SG Iron/Ductile iron is not a single material but is part of a group of materials which can be produced to have a wide range of properties through control of the microstructure. The common defining characteristic of this group of materials is the shape of the graphite. In ductile irons, the graphite is in the form of nodules rather than flakes as it is in grey iron. The sharp shape of the flakes of graphite create stress concentration points within the metal matrix and the rounded shape of the nodules less so, thus inhibiting the creation of cracks and providing the enhanced ductility that gives the alloy its name.

This nodular graphite structure inhibits the creation of linear cracks hence the ability to withstand distortion.

Other elements such as copper or tin may be added to increase tensile and yield strength while simultaneously reducing ductility. Improved corrosion resistance can be achieved by replacing 15% to 30% of the iron in the alloy with varying amounts of nickel, copper, or chromium.


Cost - When compared against steel castings SG Iron has a lower manufacturing cost.

Weight Reduction - SG Iron castings will weigh significantly lighter than the equivalent steel casting due to density, less machining allowance and the ability to cast to shape.


Ductile iron is specifically useful in many automotive components, where strength needs surpass that of aluminium but do not necessarily require steel. Other major industrial applications include off-highway diesel trucks, Class 8 trucks, agricultural tractors, and oil well pumps, etc.

SG Iron / Ductile Iron Chemical Components

Ductile iron is also called as nodular iron or SG iron. Its chemical components did not have strict range for many material standards, however, its range should be useful for buyers to evaluate the quality of cast iron.

Therefore, we filled some normal standards to show the reasonable range to ductile iron. Please remember the chemical components are only a reference, not a strict standard to the material. The foundry could adjust its chemical components according to their experience in order to meet the physical properties. So, physical properties should be the only standard to materials.


Grades - We offer all grades of SG iron which offers better corrosion, wear and heat resisting.

Manufacturing Capacity - We can manufacture up to 700 kg's

Products - Crank Gear, Separator Body Liner, Winch Drums, Elevator Blocks, Impellers, Valves, Hallow Cylinder, and other various types of S G Iron Castings (Spheroidal Graphite Iron Castings / Nodular Iron Castings)