Why Ductile?

Why Ductile?

We are successfully reducing our customers’ costs by converting steel castings, forgings, stampings and fabrications to ductile iron castings. In order to provide higher strengths, we supply all grades of Austempered Ductile Iron (ADI). The consistent chemistry of our iron provides an ideal response to austempering, which gives us an advantage when ADI is required.

Casting is also a more efficient, more cost-effective process than other metal-forming methods. Ductile Iron castings result in products that not only perform better, but also save money. Compared to using a forging, stamping or fabrication, using a casting may make more sense.

Definition of Ductile Iron

Ductile iron is a family of versatile cast irons that contain as-cast spheroidal graphite nodules. It is these graphite nodules that give ductile iron the strength and ductility that has made it commercially popular today.

By controlling the matrix microstructure, ductile iron is available in several grades ranging from ductility exceeding 18% elongation to strength in excess of 100 ksi. Austempered Ductile Iron (ADI) offers even higher strengths and wear properties than the standard grades of ductile iron by means of a specialized heat treat process.

Ductile Iron vs. Steel

Ductile iron offers cost advantages over steel fabrications and forgings. Flexibility of design, the ability to reduce a multi-component fabricated assembly to a single casting offers several obvious opportunities to save cost. Designing complex castings that are closer to near net shape results in lower overall costs when compared to forgings.

ASTM A897/ 897M-06 Grades of Austempered Ductile Iron

Minimum Properties To Meet The Specified Grade

Prior Designation Grade Tensile Strength MPa/KSI Yield Strength MPa/KSI Elongation % Impact Energy Joules/Lb-Ft Typical Hardness BHN
- 750-500-11 750 / 110 500 / 70 11 110 / 80 241-302
1 900-650-09 900 / 130 650 / 90 9 100 / 75 269-341
2 1050-750-07 1050 / 150 750 / 110 7 80 / 60 302-375
3 1200-850-04 1200 / 175 850 / 125 4 60 / 45 341-444
4 1400-1100-02 1400 / 200 1100 / 155 2 35 / 25 388-477
5 1600-1300-01 1600 / 230 1300 / 185 1 20 / 15 402-512

SAE J434 Grades Of Ductile Iron Produced By Urick


Grade Typical BHN Tensile Strength (min) Yield Strength (min) % Elongation (min)
MPa ksi MPa ksi
D400 143-170 400 58 275 40 18
D450 156-217 450 65 310 45 12
D500 187-229 500 73 345 50 6
D550 217-269 550 80 380 55 4
D700 241-302 700 102 450 65 3
D800 255-311 800 116 480 70 2