SUS304 Stainless Steel Bearings Manufacturers

SUS304 Material Properties and Bearing Design

SUS304 is the JIS designation for the classic 18-8 austenitic stainless steel (18% chromium, 8% nickel), equivalent to AISI 304 and Chinese grade 06Cr19Ni10. In bearing form, it offers a unique combination of corrosion resistance, non-magnetic behavior in the annealed state, and excellent low-temperature toughness. Unlike martensitic grades such as SUS440, SUS304 cannot be hardened by heat treatment, so our bearing design compensates through optimized raceway geometry, ball complement, and cage selection.

We manufacture SUS304 bearings with the following material characteristics:

• Chromium 18.0–20.0%, Nickel 8.0–10.5%, Carbon ≤0.08% per JIS G4303/G4305
• Self-healing chromium oxide passive layer for sustained corrosion resistance
• Non-magnetic in solution-annealed condition; slight magnetism may appear after cold working
• Tensile strength ≥520 MPa, yield strength ≥205 MPa, elongation ≥40%
• Operating temperature range from cryogenic to approximately 350°C with appropriate lubricant

Product Range: SR Series SUS304 Deep Groove Ball Bearings

Our SUS304 bearing line follows the SR (stainless inch series) nomenclature, covering bore sizes from miniature to small-bore configurations. Each series is engineered for specific load, speed, and environmental requirements. The table below summarizes our standard offering:

All series are available with open, shielded (ZZ), or sealed (2RS) configurations. We also produce flanged versions under the SFR designation for axial location in compact housings.

Application Fit and Industry Use

SUS304 bearings are specified where corrosion resistance and non-magnetic properties outweigh the lower load capacity compared to bearing steel or SUS440. Typical environments include:

Configuration Options and Customization

As a Wholesale SUS304 Stainless Steel Bearings Factory, we support both standard catalog dimensions and fully custom designs. Our engineering team works from your drawings, samples, or performance targets to define:

• Sealing systems: contact seals (2RS) for contamination resistance, non-contact shields (ZZ) for high-speed, or custom labyrinth seals for washdown
• Cage materials: stainless steel, PTFE, PEEK, or polyamide depending on temperature and chemical exposure
• Ball material: SUS304 balls for full corrosion resistance, or hybrid with ceramic balls for electrical insulation and reduced friction
• Internal clearance: C2, CN, C3, or custom preload for specific shaft-fit requirements
• Lubrication: food-grade grease, low-temperature grease, or dry-film lubricant for vacuum service

For non-standard bore sizes, special flanges, or integrated shaft assemblies, we provide prototype development and mass production under our Deep Groove Ball Bearings program.

Quality Assurance and Testing

Every SUS304 bearing lot undergoes dimensional, noise, and vibration testing before shipment. Our quality management system, certified under IATF 16949, covers incoming material verification, in-process inspection, and final acceptance. We verify material composition through SGS-tested certificates, ensuring chromium and nickel content meet JIS specifications.

Key tests performed on each production batch include:

• Radial internal clearance measurement to ISO 5753 standards
• Noise testing (BVR-type) for smooth, quiet operation below 25 dB in miniature sizes
• Vibration velocity and acceleration checks per ISO 15242
• Salt spray testing for corrosion resistance validation
• Dimensional verification of bore, OD, and width using air gauging and laser micrometers

Information We Use to Configure Your Solution

To prepare an accurate quotation and engineering proposal, we need the following project data:

Installation, Maintenance, and Service Support

We provide mounting recommendations for each bearing configuration, including shaft and housing tolerance classes, recommended fits, and lubrication intervals. For sealed bearings, no re-lubrication is required during service life. For open bearings, we supply grease specifications and relubrication schedules based on operating conditions.

Our after-sales team offers failure analysis and bearing optimization services. If a bearing fails prematurely, we examine the returned sample, identify root causes (misalignment, inadequate lubrication, contamination, or material fatigue), and recommend corrective actions. This service is available for all YHU bearing products, including our SUS316 Stainless Steel Bearings and SUS440 Stainless Steel Bearings lines.

Packaging and Delivery

Bearings are individually packaged in anti-corrosion paper or plastic tubes, then packed in export-grade cartons or wooden crates depending on quantity. We offer standard industrial packaging, retail-ready blister packs, and custom labeling for OEM distribution. For international shipments, we coordinate sea, air, or express freight with full documentation including packing lists, commercial invoices, and material certificates.

Frequently Asked Questions