Import 6214m.C4.Vl0241 Insulated Bearing — Buy in Bulk from Supplier in China

The 6214M.C4.VL0241 from Linqing Nine Star Bearing Science & Technology Co., Ltd. is an electrically insulated deep groove ball bearing with a 70mm bore, 125mm outer diameter, and 24mm width. The M designation indicates a brass cage, C4 denotes radial clearance greater than standard C3, and VL0241 specifies an aluminium oxide ceramic coating on the outer ring to block electrical current passage. This configuration targets variable-frequency drive (VFD) motor applications where shaft voltages induce bearing currents causing pitting and premature failure.

The bearing base material is through-hardened bearing steel, with the insulation layer typically plasma-sprayed aluminium oxide followed by a sealing resin to prevent moisture ingress. C4 clearance accommodates thermal expansion in high-speed or elevated-temperature operation where inner ring temperature exceeds outer ring temperature. The brass cage offers better high-speed performance than pressed steel and tolerates marginal lubrication more robustly. Standard 6214 bearings without insulation carry lower unit cost but require additional shaft or housing insulation solutions that add assembly complexity and dimensional stack-up risk.

Intended applications include traction motors, wind turbine generators, industrial VFD motors, and any rotating machinery where common-mode voltage creates circulating or shaft-discharge currents. The C4 clearance makes this bearing particularly suited to motors with aluminium housings or warm ambient operation. Buyers should confirm the coating breakdown voltage, surface resistivity, and whether the insulation is on the outer ring only (VL0241) with inner ring uncoated, or if inner ring insulation (VL2071) is also available. The listing does not state lubricant type, limiting speed, or operating temperature range, all of which must be confirmed with the supplier for correct selection.

Linqing Nine Star Bearing Science & Technology Co., Ltd. is located at Bachalu Industrial Park, Linqing, Liaocheng, Shandong Province, China, postal code 252000. The supplier carries an imported tier and harbour trust tier classification. The response rate shows zero percent with zero average response hours, indicating no reliable responsiveness data is available through the platform. No information is provided about year of establishment, registered capital, employee count, or named customers. The company name suggests specialisation in bearing technology, and the insulated product indicates focus on a niche segment within the broader bearing market.

The source description contains several claims that buyers should treat as starting points for verification rather than assured facts. References to ISO and CE certifications are mentioned in the source text but no certificate numbers or scopes are provided. The flexible MOQ claim lacks any stated quantity. The profile does not indicate production capacity, number of insulation coating lines, or whether the VL0241 coating is applied in-house or subcontracted. Buyers should conduct independent due diligence, request factory audit reports, and verify that the insulation coating process is controlled and tested rather than assuming standardised quality across all Shandong bearing producers.