Ductile iron represents the fastest growing segment of the iron market. It is a cost-effective substitute for carbon and low alloy steels, and in some applications, ductile iron can even outperform steel. By applying the two-stage heat treatment process known as austempering, the metal acquires even more advantageous properties, challenging the performance of medium grades of steel.

The qualities of ductile iron make it an ideal metal for the design freedom and precision available through investment casting. The metal and the process have the potential to provide complex parts with high dimensional accuracy, exceptional detail, and excellent economics.    Back to Top

Achieving the full potential of ductile iron requires superior metallurgical process control, as well as the highest levels of skill in part design, ceramics, and metal pouring to realize the joint benefits of ductile iron and investment casting.

Precision Metalsmiths, Inc. was one of the first investment foundries in the world to pour ductile iron as well as a pioneer in offering castings with austempered ductile iron (ADI). We maintain the demanding controls of chemistry, process procedures, timing, and temperature required to retain our certification by the Ductile Iron Society. In more than two decades of work with ductile iron alloys, proprietary processes and equipment which have been developed enable us to provide castings that take full advantage of this metal’s properties. Our ongoing research and development efforts ensure that our castings reflect the latest advancements in foundry technology.

The ductile iron family includes grades that offer specific mechanical properties required for various applications.

 Metallurgists will help you select the best alloy for your use while our engineers will carefully assess the part design for compatibility with investment casting. In addition to modifications that optimize cost efficiency, we can often suggest changes that improve the effectiveness of the finished part. If required, a process can economically provide accurate metal prototypes for testing.

Technicians machine the precision tools needed to form patterns in wax formulation. Your ductile castings are manufactured with the Shellvest^® process. A wide range of after-casting processes including austempering, heat treating, and other finishing services, can also be provided.    Back to Top

The strength and corrosion resistance of Ductile iron provides added benefits for this shifter crank used in marine outboard engines. 0.073 lbs.

• Less brittle than most types of iron.

• Lower cost than carbon and low alloy steels.

• Less gating required, lowering unit cost for both materials and labor.

• Excellent castability/high yield rate.

• Four times stronger than cast iron.

• 0% lighter in weight than steel.

• Highly machinable.

• Superior wear-resistance.

• Available in grades that offer a range of desirable properties.

• Most grades can be used in the as-cast condition without additional heat treatments.

• Offers an average 25% cost savings over forgings or steel castings.

• 100% recyclable.

• Twice as strong as untreated ductile iron.

• Fracture, fatigue, and toughness properties comparable to forged or cast steels.

• Increased toughness under abrasive conditions.

• Crack resistance that exceeds untreated ductile grades.

• Available in a wide range of mechanical properties.

The integrity of your finished parts are assured using advanced quality control methods including spectrographic analysis, carbon analysis, micro examinations, computerized measurement, and nondestructive inspections with radiographic, magnetic particle, and fluorescent penetrant technologies. And finally, each part is visually inspected by an experienced technician before delivery.
This cylinder, used in manufacturing air motors for hand-operated power grinders, combines precise casting detail with the strength of ductile iron		Computer-controlled coordinated measuring instruments are used to verify the dimensional accuracy of tools, patterns and parts.
	Technicians form the ductile alloy you specify by inoculating base iron immediately before casting. We only pour virgin metal. Our scrap ductile iron is sold for recycling in other, less demanding casting applications.
Minimum Mechanical Properties of As-Cast Ductile Iron Grade (UNS#) Castability Tensile Yield Elong Strength Machinability May Substitute for 60-40-18(F32800) Very Good 60,000 40,000 18% Lowest Easiest 1010,1020,1030 65-45-12(F33100) Very Good 65,000 45,000 12% Low Easy 4620,8620,& above 80-55-06(F33800) Very Good 80,000 55,000 6% Medium Medium 1040,4130,4140,8630,8640, & above 100-70-03(F38400) Very Good 100,000 70,000 3% Medium Medium 4330,4340,8730, & above
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Ductile Iron - ASTM A536 Grade Yield (000) Tensile (000) %E (2") 4018 40 60 18.0 4512 45 65 12.0 5506 55 80 6.0 7003 70 100 3.0 9002 90 120 2.0
Austempered Ductile Iron - ASTM A897 Grade Yield (000) Tensile (000) %E (2") Hardness  (Bhn) Impact (Ft. Lb.) 1 80 125 10 269-321 75 2 100 150 7 302-363 60 3 125 175 4 341-444 45 4 155 200 1 388-477 25 5 195 230 N/S 444-555 N/S

The Benefits of Investment Casting with Ductile Iron

• Near net shape-uses metal economically and reduces after-cast machining.
• Close tolerances-casts at an average tolerance of +/- .005 inch or better which decreases the need for after-cast straightening.
• Excellent surface Finish-yields an average, as-cast microfinish of 125 RMS; lessens or eliminates after-cast finishing requirements.
• Cast-in Detail-capable of including holes and lettering, lowers the need for costly machining.
• Design Freedom-allows simple or complex design, including intricate internal configuration.
• Wide Choice-ductile iron alloys offer different characteristics depending on how the graphite nodules appear in the matrix of metal.
• Size Range-ideal for small parts with weights from fractions of an ounce to 10 pounds.
• Tooling Economy-requires lower-cost tolling to cast high-quality parts.

Please contact us to review any of our brochures:

• The Advantages of Investment Casting Technology

• The Strength of Ferrous Alloys

• The Versatility of Aluminum & Non-Ferrous Castings

• Investment Casting Systems

• Alloy Selection Guide

• The Benefits of Ductile Iron

Precision Metalsmiths, Inc.
1081 East 200th Street
Cleveland, Ohio  44117
Telephone:  216-481-8900
Fax:  216-481-8903

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