International buyers sourcing chrome steel balls frequently encounter three bearing steel designations:
AISI 52100, GCr15, and 100Cr6.
Although these names are used under different regional material systems, they are commonly associated with closely related high-carbon chromium bearing steels.
Understanding the relationship between these designations can help buyers communicate more clearly with international suppliers.
Three Common Bearing Steel Designations
AISI 52100
AISI 52100 is a widely recognized bearing steel designation commonly used in U.S.-based purchasing specifications.
It belongs to a family of high-carbon chromium steels associated with rolling bearing components.
GCr15
GCr15 is a Chinese bearing steel designation.
It is commonly used in specifications for bearing steel balls and other bearing-related components manufactured in China.
100Cr6
100Cr6 is a European bearing steel designation, commonly associated with material number 1.3505.
It is widely referenced in European bearing steel specifications.
Are These Materials Identical?
These designations are frequently treated as comparable grades based on their general chemical composition.
For example, SKF’s reference material lists 100Cr6, 52100, and GCr15 together as comparable steel designations by composition.
However, this does not mean that every individual product supplied under these names automatically meets identical technical requirements.
Steel specifications can include more than chemical composition.
Depending on the applicable standard and customer requirements, buyers may need to consider:
- Chemical composition limits
- Material cleanliness
- Heat treatment requirements
- Mechanical and metallurgical properties
- Inspection and acceptance criteria
- Traceability and documentation
Therefore, an equivalent material designation should not replace the need to review the actual purchase specification.
Material Grade vs Steel Ball Precision Grade
Another important distinction concerns the steel material and the finished ball precision grade.
AISI 52100, GCr15, and 100Cr6 describe bearing steel materials.
G10 describes a precision classification for a finished steel ball.
For example, a purchasing specification might require a particular bearing steel material together with G10 precision under ISO 3290-1:2014.
These specifications address different aspects of the product.
What Should International Buyers Specify?
When requesting chrome steel balls, buyers should include:
- Required material designation
- Applicable material standard
- Nominal ball diameter
- Precision grade and applicable ball standard
- Quantity and intended application
- Required inspection and documentation
If alternative material grades are acceptable, the RFQ should clearly state whether substitutions require prior approval.
Sourcing Precision Chrome Steel Balls
BOYA Industries works with experienced manufacturing partners in China to coordinate precision steel ball sourcing and technical requirements.
Our core product focus includes G10 chrome steel balls for bearing and industrial applications.
Visit our Chrome Steel Balls product page to learn more.
If you have a material specification or a drawing, send it with your RFQ so that the requirements can be reviewed before quotation.
Designation comparison for an RFQ
| Designation | Common context | What to confirm |
|---|---|---|
| AISI 52100 | U.S. bearing steel specifications | Governing material standard, edition and acceptance requirements |
| GCr15 | Chinese bearing steel specifications | Governing GB/T standard, delivery condition and material documentation |
| 100Cr6 / 1.3505 | European bearing steel specifications | Governing European standard, delivery condition and approval of alternatives |
These names are a starting point for specification review, not blanket approval to substitute one steel for another.
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