AISI M2 Balls
Ball Bearing
High-Speed Steel, Wear-Resistant & Heat-Tolerant
AISI M2 balls from Atlas Ball & Bearing are manufactured from premium high-speed steel, delivering exceptional hardness, superior wear resistance, and excellent performance at elevated temperatures. These precision balls are ideal for demanding industrial and tooling applications where durability and dimensional stability are critical.
Produced from high-quality AISI M2 high-speed steel, these balls maintain strength and surface integrity under heavy loads and high operating speeds, outperforming many standard carbon and alloy steels in severe working environments.
150
Precision Ball Diameter
Why Choose AISI M2 Balls?
AISI M2 is a widely used molybdenum-based high-speed tool steel known for its excellent combination of hot hardness, wear resistance, and toughness. It retains cutting-edge strength at elevated temperatures and performs reliably in high-friction, high-load environments.
Compared to standard bearing steels, AISI M2 offers improved resistance to softening under heat and superior durability in abrasive conditions.
Key Benefits
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Extremely high hardness and wear resistance
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Excellent hot hardness and heat tolerance
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High compressive strength
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Good toughness for a high-speed steel
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Superior performance in abrasive environments
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Stable dimensional accuracy
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Long service life in demanding applications
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Suitable for tooling and high-load components
Manufacturing & Supply
We are capable of manufacturing and supplying loose AISI M2 steel balls in nearly every variation of grade, maintaining an extensive stock with sizes ranging from 0.2mm to 150mm in diameter.
Please feel free to rate our products and service or send us your comments by using our form opposite →
Additionally, we offer a bespoke ball manufacturing service, which follows the same process controls and traceability but uses a customer’s own material. For further details, please email us or call +44 (0) 1922 710515.
Applications
AISI M2 balls are widely used in high-wear, high-temperature, and tooling environments where standard bearing steels may not perform adequately.
Typical applications include:
Tooling and cutting equipment
High-load industrial machinery
Precision bearings in harsh environments
Wear-resistant components
Automotive and aerospace tooling systems
Oil, gas, and heavy engineering equipment
AISI M2 balls are available in multiple sizes and tolerances to meet wear-critical and high-performance engineering requirements.
Why Atlas Ball & Bearing?
UK-based manufacturer and worldwide supplier of precision steel balls
Extensive stock with rapid UK and international delivery
Wide range of sizes, grades, and tolerances
Expertise in high-performance tool steels
Consistent quality, surface finish, and full traceability
Related Materials

Useful terms and definitions
Batch or Lot:
A defined quantity of balls manufactured under conditions presumed to be uniform and which is considered an entity.
Nominal Ball Diameter:
The diameter value that is used for the general identification of a ball size.
Single Ball Diameter:
The distance between two parallel planes tangential to the actual ball surface.
Diameter Tolerance per Batch:
The allowed difference between the smallest measured ball diameter and the largest ball diameter within the same batch or lot quantity.
Sphericity:
A measure of roundness expressed as the difference between the measured roundness of a ball and a theoretically perfectly round ball.
Surface Finish or Roughness:
A measure of the texture of a surface. It is quantified by the vertical deviations of the actual surface from its ideal form. If these deviations are large, the surface is rough; if they are small, the surface is smooth.
Ball Grades
| Grade | Diameter Tolerance per Ball | Sphericity | Diameter Tolerance per Unit Container | Basic Diameter Tolerance | Maximum Surface Roughness Micro | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| Inch | µ | Inch | µ | Inch | µ | Inch | µ | Inch | µ | |
| 3 | .000003 | 0.076 | .000003 | 0.076 | .000005 | 0.127 | ±.00003 | ± 0.076 | 0.5 | 0.013 |
| More details about Grade 3... | ||||||||||
| 5 | .000005 | 0.127 | .000005 | 0.127 | .00001 | 0.25 | ±.00005 | ± 0.127 | 0.8 | 0.02 |
| More details about Grade 5... | ||||||||||
| 10 | .000010 | 0.25 | .000010 | 0.25 | .00002 | 0.51 | ±.0001 | ± 2.5 | 1.0 | 0.025 |
| More details about Grade 10... | ||||||||||
| 15 | .000015 | 0.38 | .000015 | 0.38 | .00003 | 0.76 | ±.0001 | ± 2.5 | 1.2 | 0.03 |
| More details about Grade 15... | ||||||||||
| 25 | .000025 | 0.63 | .000025 | 0.63 | .00005 | 1.27 | ±.0001 | ± 2.5 | 1.5 | 0.038 |
| More details about Grade 25... | ||||||||||
| 50 | .00005 | 1.27 | .00005 | 1.27 | .0001 | 2.5 | ±.0002 | ± 5 | 3.0 | 0.075 |
| More details about Grade 50... | ||||||||||
| 100 | .0001 | 2.5 | .0001 | 2.5 | .0002 | 5 | ±.0005 | ± 5 | 5.0 | 0.125 |
| More details about Grade 100... | ||||||||||
| 200 | .0002 | 5 | .0002 | 5 | .0004 | 10 | ±.0010 | ± 10 | 8.0 | 0.2 |
| More details about Grade 200... | ||||||||||
| 300 | .0003 | 7.5 | .0003 | 7.5 | .0006 | 15 | ±.0015 | ± 37.5 | N/A | N/A |
| More details about Grade 300... | ||||||||||
| 500 | .0005 | 12.5 | .0005 | 12.5 | .001 | 25 | ±.002 | ± 50 | N/A | N/A |
| More details about Grade 500... | ||||||||||
| 1000 | .001 | 25 | .001 | 25 | .002 | 50 | ±.005 | ± 125 | Not Applicable | Not Applicable |
| More details about Grade 1000... | ||||||||||
| 2000 | .002 | 50 | .002 | 50 | .004 | 100 | ±.005 | ± 125 | N/A | N/A |
| More details about Grade 2000... | ||||||||||
Sample Our Work!
Take the first step towards precision and quality with our expert services. At Atlas Ball & Bearing, we’re committed to delivering top-notch precision balls and rollers for a wide range of industries, including gas, oil, medical, and transportation. Our dedicated team is ready to assist you with custom solutions tailored to your specific needs. Experience the Atlas Ball & Bearing difference now!