Product Overview
Bearing steel round bar is high-carbon chromium alloy steel engineered for components subjected to high mechanical stress, rolling fatigue, and continuous friction. Our bars are produced via Electric Arc Furnace (EAF) followed by Ladle Refining (LF) and Vacuum Degassing (VD), ensuring low gas content and strict control over non-metallic inclusions.
Supplied in annealed condition for machinability, these bars serve as the primary raw material for precision bearings, automotive powertrain components, and high-load industrial hardware. Mill production adheres strictly to international standards including ASTM A295, DIN 17230, and JIS G4805 under an IATF 16949 certified quality management system.
Technical Specifications
|
Standard Grades |
AISI 52100 / 100Cr6 / GCr15 / SUJ2 / EN31 |
|
Diameter Range |
Hot Rolled: 16 mm - 250 mm; Cold Drawn / Peeled: 15 mm - 160 mm |
|
Length |
3,000 mm - 6,000 mm (Custom lengths available upon request) |
|
Delivery Condition |
Soft Annealed (+A), Quenched and Tempered (+QT), or Cold Drawn (+C) |
|
Surface Finish |
Hot Rolled (black), Turned & Peeled (P), Centerless Ground (CG), Polished |
|
Hardness (Annealed) |
Maximum 207 HBW / 229 HBW depending on grade |
|
Microstructure Requirements |
Spheroidized pearlite structure; carbide network rating <= Grade 2 per ASTM E45 / ISO 4967. |
Product Advantages
Control of Non-Metallic Inclusions:
Vacuum degassing limits oxide and silicate inclusions, preventing premature fatigue spalling in finished bearing raceways.
Carbide Homogeneity:
Controlled cooling rates during rolling minimize carbide segregation, ensuring uniform hardness response after final heat treatment.
Tight Dimensional Tolerances:
Centerless grinding and precision peeling achieve ISO h9/h11 tolerances, reducing stock removal during downstream machining.
Traceability:
Each heat number is stamped on bars and mapped directly to independent spectrometer and ultrasonic test reports.
Applications
Rolling Bearings: Deep groove ball bearings, tapered roller bearings, and cylindrical roller bearings operating under high radial loads.
Automotive Powertrain: Transmission shafts, CV joint components, pump shafts, and steering gear components.
Industrial Hardware: High-precision guide rails, machine tool spindles, ball screws, and hydraulic plungers.
Customization & Processing
Saw Cutting:
Precision cutting to exact client lengths with zero end-face burrs.
Heat Treatment Support:
Controlled atmosphere spheroidize annealing and stress-relieving services.
Surface Machining:
In-house turning, peeling, and grinding to prepare bars for automated CNC lathe feeding.
Testing Adaptation:
Third-party inspection by SGS, TÜV, or BV available prior to dispatch.
Quality Control & Inspection
Manufacturing relies on integrated metallurgical controls from raw material casting to final packaging.
Chemical Analysis: Optical Emission Spectrometer (OES) checks exact carbon, chromium, manganese, and silicon content per ladle.
Metallographic Examination: Microscopic analysis verifies grain size (ASTM grain size 6 or finer) and decarburization depth limits.
Nondestructive Testing (NDT): 100% ultrasonic testing (UT) performed per ASTM A388 or SEP 1921 to detect internal micro-cracks and centerline shrinkage.
Hardness Testing: Brinell and Rockwell hardness testing conducted on test coupons from every heat batch.
Packaging & Shipping
Packaging Method:
Bundled with heavy-duty steel strapping, wrapped in moisture-resistant woven plastic, and optionally packed in wooden crates for export.
Rust Prevention:
Anti-rust oil coating applied to all bare metal surfaces prior to bundling; VCI paper interleaving available for sea freight shipments.
Logistics:
Direct loading from warehouse to container or flatbed truck via 10-ton overhead cranes. Standard port of export: Qingdao or Shanghai, China.
FAQ
Q: What is the difference between hot-rolled and peeled bearing steel bars?
A: Hot-rolled bars retain surface scale and possess standard mill tolerances, making them suitable for heavy forging or rough machining. Peeled bars have outer surface defects, decarburization layers, and scale removed via turning, providing exact diameter control ready for direct CNC loading.
Q: Do you supply Mill Test Certificates (MTC) with the shipment?
A: Yes. Every shipment includes an original MTC conforming to EN 10204 3.1, detailing exact chemical composition, mechanical test results, hardness values, and ultrasonic test compliance.
Q: What is the typical lead time for standard stock vs. custom dimensions?
A: Ex-stock standard grades (e.g., GCr15 / AISI 52100 diameters 30-150 mm) ship within 7 to 10 days. Custom rolling or peeled bars requiring specific length tolerances or annealing take 25 to 35 days.
Q: Can you guarantee low oxygen and inclusion levels for high-load applications?
A: Yes. Through secondary refining (LF+VD), total oxygen content is maintained below 15 ppm, and inclusion ratings strictly adhere to ASTM E45 Method A limits (Type A, B, C, D <= 1.5).
Q: What is the minimum order quantity (MOQ) for non-standard diameters?
A: MOQ typically starts at 3 metric tons per size for custom rolling. For standard stock sizes, smaller trial orders are accommodated based on current warehouse availability.
Q: What anticorrosion protection is used for ocean freight?
A: Bars are coated with a heavy-duty solvent-based rust preventative oil and bundled securely. For shipments traversing high-humidity maritime routes, VCI (Volatile Corrosion Inhibitor) plastic wrapping is applied inside standard woven outer layers.
Request a Quote
Provide your required steel grade, diameter, length, quantity, and target delivery port to receive a formal quotation with mill test samples within 24 hours.
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