Sill Bearing
Sill Bearing
Direct access to our certified manufacturing output catalog. High-performance mechanical assemblies optimized for industrial application.
The 6304 Z deep groove ball bearing represents one of the most widely specified mechanical components across high-load, high-precision industrial domains. Belonging to the ISO 6300 series of medium-dimension radial bearings, the 6304 Z configuration features a single metal shield ("Z") designed to protect the internal rolling elements from large particulate ingress while maintaining low-friction rotational operation.
Manufactured from premium-grade GCr15 high-carbon chromium bearing steel (equivalent to AISI 52100 or 100Cr6), the bearing boasts optimized grain alignment and uniform hardness after advanced induction quenching and tempering. The physical dimensions conform strictly to ISO standards: an inner diameter (bore) of 20mm, an outer diameter of 52mm, and a width profile of 15mm. These parameters allow the bearing to manage high radial loads alongside moderate axial thrust forces in both directions.
For applications demanding high structural integrity and minimum acoustic signatures, SILL BEARING utilizes state-of-the-art superfinishing processes on both the inner and outer ring raceways. This reduces micro-roughness values (Ra) to less than 0.05μm, significantly extending the L10 fatigue life expectancy under dynamic stress conditions.
Detailed dimensional, chemical, and operational variables of the 6304 Z deep groove ball bearing designed and manufactured in our facilities.
| Parameter / Feature | Standard Metric Specification | Engineering Benefit & Application Utility |
|---|---|---|
| Inner Diameter (d) | 20 mm | Optimized for medium-duty shafts in electric motors & gearboxes. |
| Outer Diameter (D) | 52 mm | Fits standard housing profiles; delivers high load capacity. |
| Width / Thickness (B) | 15 mm | Ensures structural rigidity against angular deflection. |
| Basic Dynamic Load Rating (Cr) | 15.9 kN | Calculated for long life cycles under continuous high-speed rotation. |
| Basic Static Load Rating (C0r) | 7.8 kN | Ensures high resistance to permanent deformation under heavy load peaks. |
| Limiting Speed (Grease) | 13,000 RPM | Single metal shield permits low-friction thermal dissipation. |
| Material Composition | GCr15 Chromium Steel (HRC 60-65) | High wear resistance, excellent rolling fatigue strength. |
| Standard Clearances | CN, C3, C4 available | C3 clearance optimizes thermal expansion tolerances at peak speeds. |
Strategically situated in the affluent and industrially advanced Hangzhou Bay New Zone, SILL BEARING FACTORY benefits from world-class infrastructure and logistics networks. The factory enjoys immediate proximity to the two largest maritime gateways in China: the Shanghai Port and the Ningbo Port. Additionally, the facility is adjacent to the Hangzhou-Ningbo Expressway, the 329 State Line highway network, and the Hangzhou-Ningbo Railway Line. International buyers and technical consultants can reach our offices in just 90 minutes from either Hangzhou Xiaoshan Airport or Ningbo Lishe Airport.
To scale our output alongside growing global demand, our new advanced production facility, Anhui TOPB IMP.&EXP. Co., Ltd., is under construction. Once commissioned, this smart factory will expand our annual production capacity by an estimated $20 million, deploying next-generation automated grinding, cleaning, and packing suites.
Under our proprietary brands SILL and NETB (with full OEM support), we specialize in the design, research, and fabrication of Deep Groove Ball Bearings (ranging from ￠4mm to ￠120mm), Tapered Roller Bearings, and engineered non-standard bearings. We use exclusively superior GCr15 bearing steel to guarantee performance that excels under severe operating pressures.
Explore our foundational engineering solutions, classified by load capability, kinematic precision, and geometric orientation.
Versatile, self-retaining bearings with deep groove raceways designed to support moderate radial and axial loads in both directions. Features low friction coefficients, reduced noise output, and minimal maintenance overhead. Ideal for high-speed motor designs.
Engineered with separate inner and outer rings containing tapered raceways. Designed dynamically to support massive combined radial and axial thrust loads. Available in single-row, double-row, and heavy-duty four-row arrangements to match application demands.
Optimized to carry significant unidirectional axial loads. A larger contact angle correlates directly to enhanced axial load carrying capacity, critical for precision machine tool spindles and heavy-duty hydraulic pumps.
Combines a radial needle bearing configuration with thrust bearing elements. This design offers a compact envelope, low cross-sectional height, high rotation precision, and excellent radial load tolerance, perfect for tight packaging constraints in automotive transmissions.
Premium standard bearings produced across our production complexes, engineered to exceed ISO and DIN guidelines.
Our commitment to a 100% customer acceptance rate is realized through a systematic, multi-tiered quality control protocol.
Spectrographic and metallographic verification of incoming GCr15 chromium steel. Each batch of steel must conform to rigorous chemical composition tolerances prior to entering the forging lines.
Machinists utilize real-time pneumatic gauges and digital micrometers at each grinding station, keeping a close eye on ring geometry, roundness, and raceway groove profile stability.
Every single unit undergoes automated dimensional mapping and acoustic testing. Critical tolerances, including radial runout, clearance class, and high-frequency noise levels, are verified.
Independent audits are conducted on completed batches using AQL (Acceptance Quality Limit) procedures. Samples undergo destructive testing to check hardness and internal crystalline structures.
Prior to grease packing and protective wrapping, bearings are audited for surface finish, marking clarity, shield integrity, and anti-rust packaging. Zero defective components are permitted to leave the facility.
A closer look at how the 6304 Z bearing performs across global and local industrial environments.
Deep groove ball bearings with a single Z shield are highly suited for environments where mechanical components require external protection, but are housed within secondary dust-proof structures. The single shield design minimizes drag, helping reduce energy consumption in high-efficiency machinery.
How SILL BEARING leverages industrial clusters, logistical networks, and lean processes to secure a global competitive advantage.
Our location in the Hangzhou Bay New Zone places us in the heart of China’s bearing manufacturing hub. This proximity allows us to secure high-grade raw materials, heat treatment services, and specialized tooling at competitive rates and with short lead times.
With direct highway connections to both Ningbo Port (the world’s largest port by cargo tonnage) and Shanghai Port, we can optimize shipping routes, minimize port delays, and offer flexible freight options (FOB, CIF, DDP) to global buyers.
The construction of our new factory, Anhui TOPB IMP.&EXP. Co., Ltd., reflects our focus on meeting growing demand. This new facility will feature advanced automation, helping insulate our clients from supply shortages and cost fluctuations.
Addressing future demands for low-carbon manufacturing, high-temperature tolerance, and smart-sensor integration.
The global bearing market is shifting toward lighter components, higher speeds, and reduced environmental impact. SILL BEARING is adapting to these trends by implementing a technical development roadmap focused on three key areas:
By diffusing nitrogen and carbon into the steel’s surface layer, we are improving the wear resistance of our 6304 Z bearings under contaminated lubrication conditions. This process helps extend the service life of bearings in demanding industrial and agricultural gearboxes.
In partnership with leading synthetic lubricant manufacturers, we are developing specialized greases that maintain their viscosity across a wide temperature range (-40°C to +180°C). This helps minimize grease leakage and extend maintenance intervals.
At both our Hangzhou Bay and Anhui facilities, we are upgrading to energy-efficient grinding systems, recycling processing fluids, and integrating solar power to reduce the carbon footprint of our operations.
Acoustic Performance: Shifting our baseline production of deep groove ball bearings to Z3 and Z4 vibration grades for silent operation in EV components.
Corrosion Resistance: Developing thin-film ceramic coatings and specialized zinc-nickel plating options to protect bearings used in marine and high-humidity environments.
Service Life: Aiming to increase the standard L10 life of our GCr15 bearings by 25% through advanced steel refining and raceway finishing.
Ensuring compliance with international standards and providing reliable support for global buyers and engineering teams.
Our manufacturing lines operate under ISO 9001:2015 and IATF 16949 quality management systems. This ensures consistent tolerances, reliable material traceability, and clear process documentation.
Our products comply with RoHS and REACH regulations. We use lead-free materials, non-toxic rust preventatives, and eco-friendly packaging materials.
We offer customized engineering services, including custom grease fills, non-standard clearances, laser-etched markings, and customized packaging options to match your brand requirements.
Detailed answers to common technical queries about the 6304 Z deep groove ball bearing.
Partner with SILL BEARING for OEM/ODM support, certified GCr15 quality, and efficient logistics. Let our engineering team help optimize your supply chain.
Contact Our Engineering Team NowExplore our specialized range of high-performance bearings, designed to meet demanding operational conditions.
