Quality Control in Bearing Manufacturing
Quality control is not a single step — it‘s a multi‑stage process beginning before production and extending through final packaging. At Luoyang Ouna Bearing, we view every phase as a vital checkpoint.
Stage 1: Incoming Quality Control (IQC)
Before any material enters our production line, it undergoes verification. Bearing steel is tested for composition; hardness samples are checked against HRC 60-62 targets; and certifications are reviewed against purchase orders. Defective material is rejected immediately.
Stage 2: In‑Process Control (IPC)
During manufacturing, we monitor critical parameters — grinding wheel speeds, cooling lubricant flow, and dimensional readings. Touch‑trigger probes on automatic lathes measure key dimensions after each machining operation, enabling real‑time tool compensation to correct for wear [4†L28-L32]. This ongoing feed reduces error propagation downstream.
Stage 3: Final Inspection
Every finished bearing is inspected before shipment. We verify:
Outer diameter runout (≤5μm for P5, ≤1μm for P2)
Rotational accuracy on matched test spindles
Hardness uniformity (HRC 60-61 across raceways)
Microstructure integrity (no cracks, voids, or surface defects)
Lab microscopes spot surface defects invisible to the naked eye, while vibration and acoustic emission data confirm smooth running [4†L17-L21].
Traceability and documentation
From raw steel lot numbers to final test reports, every Ouna bearing carries full traceability. International buyers receive complete quality documentation with their shipments — enabling straightforward verification and faster customs clearance.
Quality as our foundation
Our quality system has been aligned with ISO standards since our founding in 2014. The same bearings we sell to European CNC builders and robotic integrators undergo identical QC procedures. When you source from Ouna, you‘re not just buying components — you‘re buying a documented quality commitment.
Request our quality control documentation with your next inquiry — see for yourself how we maintain precision from material to finished product.





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