Selecting the correct material for the application is not only about choosing the highest grade and the highest strength when it comes to ADI grades and applications. While Austempered Ductile Iron (ADI) has an outstanding combination of strength, toughness, ductility, fatigue and wear resistance, the various grades are developed to meet different engineering requirements.
The real question for OEMs and component designers is not, “Which ADI grade is strongest?” It is:
“Which ADI grade offers the accurate balance of properties for my applications?”
Here at Castwise Manufacturing Company, we understand that the first step towards creating quality and consistent casts is in choosing your materials. We have over 30 years of foundry experience, with our aim to assist our customers in selecting and producing the casting to meet their functional and performance needs.
Quick Brief of ADI grades and applications
Before discussing individual grades, here is a brief overview and comparison of where each grade fits.
ADI Grade: 900/9
- Strength: Moderate
- Ductility: High
- Ideal Performance Focus: Toughness and dynamic loading
- Typical Applications: Automotive, brackets, suspension
ADI Grade: 1050/7
- Strength: High
- Ductility: Good
- Ideal Performance Focus: Strength and toughness balance
- Typical Applications: Gears, hubs, shafts
ADI Grade: 1200/5*
- Strength: Very High
- Ductility: Moderate
- Ideal Performance Focus: High load-bearing capability
- Typical Applications: Heavy machinery, gears
ADI Grade: 1400/1*
- Strength: Extremely High
- Ductility: Lower
- Ideal Performance Focus: Strength and wear resistance
- Typical Applications: Mining, heavy-duty components
ADI 900/9- When Toughness Matters
When high tensile strength is required while keeping reasonably high ductility, ADI 900/9 is an optimum choice. The standard ASTM 900/650/9 is also available with a minimum tensile strength of 900 MPa and elongation of 9%. This is a good choice when components are subject to varying loads, impact or dynamic stresses. Castings for automotive and suspension parts, structural brackets, steering parts and other dynamically loaded castings are all potential applications.
ADI 1050/7 - The Balanced Performer
Have you ever thought about what if your component requires more strength yet still retains desirable ductility? This is where ADI 1050/7 can come in handy. Conventional ASTM 1050/750/7 grade is a combination of 1050 MPa minimum tensile strength + 7% elongation. It offers a great balance between strength and ductility, suitable for a variety of challenging engineering parts.
Potential applications include:
- Gears and parts of power transmission
- Hubs and shafts
- Automotive components
- Industrial machinery parts
- Load-bearing castings
For many applications, ADI 1050/7 is a wise choice. It is strong enough for many demanding loads without moving too far towards the lower level of ductility that is linked with higher strength grades.
ADI 1200/5- When Loads Get Serious
When the loads of the components get heavier, designers will have to shift towards the higher strength of ADI. The grade 1200 MPa is one that can give significantly more strength than grade 900 and 1050. The 1200/850/4 is a standard specification as defined by ASTM A897/A897M, and if needed, 1200/5 should be checked against the customer's governing specification.
ADI 1400/1- Maximum Strength for Demanding Applications
In the upper range, at 1400MPa strength, 1400 MPa-class ADI is designed to be used in applications that demand the highest mechanical properties. It also conforms to ASTM, which is normally designated as 1400/1100/2. Each customer can have individual specifications, where other combinations of properties are required, which must be validated before production at all times.
Heavy-duty gears, industrial components that are subject to wear, mining parts and high-load transmission components are among the uses that can be appropriate for this grade class.
Why is it important to choose the appropriate grade of ADI?
As with ADI grades and applications, it is best to begin with the operating conditions of the component rather than selecting a specific grade based only on tensile strength.
High Ductility and Toughness
- Grade to Consider: ADI 900/9
Balanced Strength and Ductility
- Grade to Consider: ADI 1050/7
High Load-Bearing Capability
- Grade to Consider: ADI 1200/5*
Very High Strength and Wear Resistance
- Grade to Consider: ADI 1400/1*
Why does selecting the right ADI casting supplier matter?
Choosing the right grade is just one step towards making a quality ADI part. Other factors that affect performance are metallurgical control, nodularity, chemical composition, casting quality, section thickness, heat treatment, dimensional accuracy, and inspection.
As a high-strength ductile iron castings manufacturer, Castwise Manufacturing Company will bring precision casting and full in-house machining and inspection. We provide the complete solution for OEMs that require an ASTM A897 castings supplier, including DFM reviews, prototyping, tooling, casting, machining, PPAP documentation, testing and final inspection.
Consistent production is supported by ISO 9001:2015 and CQI-27 certified systems, a metallurgical and Sand Testing laboratory, spectrometer analysis, tensile and hardness testing, CMM inspection and machining skills.
Wrapping Up
There is no ‘best' ADI grades and applications.
For applications where ductility and toughness are important, ADI 900/9 can be used. The ADI 1050/7 has a balanced performance profile. Higher load requirements can be met by using ADI 1200/5, and very high strength and wear resistance applications can be met with ADI 1400/1.
You can trust Castwise Manufacturing Company, as we are the best ASTM A897 castings supplier and have been casting for more than 30 years. Moreover, we have an expert team to bring that material decision to the next level of precision-engineered casting, ready for production.