Steel balls For Bearing
Premium precision bearing balls for deep groove, angular contact, thrust, miniature, and linear motion bearings. Available in AISI 52100 chrome steel, 440C stainless, carbon steel, and ceramic — from G3 super precision to G1000 commercial grade. 0.3 mm to 250 mm diameter.
Precision Bearing Balls for Every Application
Ball bearings are the most widely used rolling-element bearing in the world — and at their heart lies the bearing ball. The performance, lifespan, and reliability of any ball bearing depend directly on the quality of its balls: dimensional accuracy, sphericity, surface finish, and material integrity.
At Jiaxin Steel Ball, we have manufactured precision bearing balls for over 30 years, supplying Fortune 500 bearing manufacturers, automotive Tier 1 suppliers, and precision equipment OEMs across 40+ countries. Our bearing balls are produced to ISO 3290 / ABMA 3 standards and certified under ISO 9001:2015.
We produce over 500 million bearing balls annually, covering the full spectrum from miniature balls (0.3 mm) for micro bearings to large-diameter balls (250 mm) for heavy industrial slewing rings.
ISO 9001
Certified
30+ Years
Experience
0.3–250mm
Size Range
G3–G60
Precision
AISI 52100 Chrome Steel
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Hardness (HRC): 60–67
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Max Operating Temp: 150°C (300°F)
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Corrosion Resistance: Low
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Best For: General purpose, high-load bearings, automotive, electric motors
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Common Grades: G10, G16, G25, G40
AISI 316 Stainless Steel
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Hardness (HRC): 25–35 (annealed)
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Max Operating Temp: 200°C (390°F)
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Corrosion Resistance: Very High
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Best For: Chemical processing, offshore, highly corrosive environments
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Common Grades: G100, G200
AISI 440C Stainless Steel
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Hardness (HRC): 57–65
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Max Operating Temp: 200°C (390°F)
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Corrosion Resistance: High
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Best For: Corrosive environments, food processing, marine, medical
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Common Grades: G10, G16, G25, G40
Si₃N₄ Ceramic
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Hardness (HRA): 75–80
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Max Operating Temp: 800°C+ (1470°F+)
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Corrosion Resistance: Excellent
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Best For: Ultra-high-speed spindles, non-magnetic, vacuum, high-temp
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Common Grades: G5, G10, G16
AISI 1010/1020 Carbon Steel
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Hardness (HRC): 58–65 (case)
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Max Operating Temp: 120°C (250°F)
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Corrosion Resistance: Low
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Best For: Low-speed, high-load industrial bearings, agriculture
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Common Grades: G100, G200, G500
Bearing Ball Materials
The material selection determines load capacity, speed rating, corrosion resistance, and operating temperature range. We offer five material options for bearing applications:
Material Selection Guide
The most common bearing ball material is AISI 52100 chrome steel (1.3505 / 100Cr6), offering the best balance of hardness, wear resistance, and cost. For corrosive environments, upgrade to AISI 440C stainless steel. For the highest speeds and temperatures, silicon nitride (Si₃N₄) ceramic balls — 40% lighter than steel with hardness exceeding HRC 78 — deliver superior performance at a premium.
GRADE G3
Tolerance: ±0.08 µm · Sphericity: 0.08 µm · Ra: 0.012 µm
Best for: Ultra-precision spindles, aerospace gyroscopes
Grade G10
Tolerance: ±0.25 µm · Sphericity: 0.25 µm · Ra: 0.016 µm
Best for: Precision bearings, automotive wheel hubs
Grade G25
Tolerance: ±0.65 µm · Sphericity: 0.65 µm · Ra: 0.030 µm
Best for: General industrial bearings, conveyors
Grade G200–G1000
Tolerance: ±5–25 µm · Sphericity: 5–25 µm · Ra: 0.12–0.30 µm
Best for: Low-speed, high-load, construction equipment
Grade G5
Tolerance: ±0.13 µm · Sphericity: 0.13 µm · Ra: 0.014 µm
Best for: Machine tool spindles, high-speed bearings
Grade G16
Tolerance: ±0.25 µm · Sphericity: 0.25 µm · Ra: 0.016 µm
Best for: Precision bearings, automotive wheel hubs
Grade G40
Tolerance: ±1.0 µm · Sphericity: 1.0 µm · Ra: 0.050 µm
Best for: Agricultural equipment, fans, blowers
Grade G100
Tolerance: ±2.5 µm · Sphericity: 2.5 µm · Ra: 0.080 µm
Best for: Heavy-duty industrial, mining, crushers
Bearing Ball Precision Grades
Precision grades are defined by ISO 3290 / ABMA 3 standards, covering diameter tolerance, sphericity (deviation from true round), surface roughness (Ra), and lot uniformity. Lower grade number = tighter tolerance = higher precision.
Bearing Ball Precision Grades
Our bearing balls are precision-engineered for the full spectrum of ball bearing designs:
Deep Groove Ball Bearings
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Typical Material: 52100 Chrome
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Common Grade: G10–G40
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Diameter Range: 0.3 – 80 mm
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Key Requirements: High sphericity,, good hardness
Miniature Bearings
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Typical Material: 440C, Si₃N₄
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Common Grade: G3–G10
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Diameter Range: 0.3 – 10 mm
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Key Requirements: Ultra-precision, low noise, consistent dimensions
Angular Contact Bearings
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Typical Material: 52100, 440C
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Common Grade: G5–G16
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Diameter Range: 1 – 50 mm
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Key Requirements: Tight diameter tolerance, excellent surface finish
Self-Aligning Bearings
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Typical Material: 52100, 440C
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Common Grade: G16–G40
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Diameter Range: 2 – 100 mm
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Key Requirements: Good sphericity, moderate precision
Thrust Ball Bearings
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Typical Material: 52100, Carbon
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Common Grade: G25–G100
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Diameter Range: 3 – 150 mm
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Key Requirements: High compressive strength, wear resistance
Linear Motion Bearings
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Typical Material: 52100, 440C
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Common Grade: G10–G25
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Diameter Range: 1 – 40 mm
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Key Requirements: Excellent roundness, smooth surface, consistent lot quality
Bearing Ball Precision Grades
Each bearing ball undergoes a tightly controlled 7-stage process to ensure it meets its specified grade:
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Cold Heading / Forging — Wire rod (52100, 440C, or specified alloy) is cut and cold-formed into rough spherical blanks.
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Flashing (Soft Grinding) — The flash line from heading is removed; ball is brought close to final diameter.
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Heat Treatment — Through-hardening for 52100 (850°C quench + temper) or case-hardening for carbon steel. 440C receives precipitation hardening for optimal corrosion resistance.
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Hard Grinding — Parallel plate grinders refine size and sphericity to within grade tolerance.
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Lapping & Polishing — Final surface finish achieved using abrasive compounds. Target Ra reached for specified grade.Inspection & Sorting — 100% automated optical sorting. Dimensional, hardness, and microstructure verification per ANSI/ASQ Z1.4 sampling plans.
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Cleaning & Packaging — Ultrasonic cleaning, rust-prevention oil coating, sealed packaging per customer spec. Full material traceability with batch records retained 10+ years.
Quality Control & Certifications
Every batch of bearing balls is subjected to rigorous quality control before shipment:
Dimensional Inspection
100% automated optical sorting for diameter, sphericity, and surface defects. Statistical sampling per ANSI/ASQ Z1.4.
Hardness Testing
Rockwell C hardness verified per batch. 52100: HRC 60–67. 440C: HRC 57–65. Carbon: HRC 58–65 (case).
Material Certification
MTC per EN 10204 3.1. Chemical composition analysis, microstructure, and inclusion rating included.
ISO 9001:2015
Factory quality management system certified and annually audited. Full batch traceability, 10-year record retention.
Standards Compliance
Our bearing balls comply with the following international standards:
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ISO 3290-1 — Steel balls for rolling bearings
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ABMA 3 / ANSI B3.3 — American bearing ball standard
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DIN 5401 — German bearing ball standard
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JIS B 1501 — Japanese standard for steel balls
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GBT 308.1 — Chinese national standard