Standard Radial Clearance Values for Deep Groove Ball Bearings Used in AGV & Industrial Automation

The core answer for AGV procurement teams: ISO 5753 defines three standard radial clearance groups for deep groove ball bearings—C2 (small), CN (general, most common), and C3 (large)—with values calculated by bearing inner diameter (D, in mm). CN group ranges from 0.001×D to 0.002×D, C3 from 0.002×D to 0.003×D, and C2 from 0.0005×D to 0.001×D. For example, a 6202 bearing (15mm inner diameter) has CN clearance of 0.015mm–0.03mm and C3 clearance of 0.03mm–0.05mm.

What Standard Radial Clearance Groups Are Defined for Deep Groove Ball Bearings?

ISO 5753 is the international benchmark for bearing radial clearance, specifying three primary groups. C2 group offers minimal clearance, ideal for light-load, low-friction applications like AGV idle rollers. CN is the general-purpose group, covering 70% of industrial bearing uses. C3 group provides wider clearance to accommodate thermal expansion or heavy shock loads. Clearance calculations rely on inner diameter, not outer diameter, a detail often overlooked in quick procurement checks.

Which Clearance Group Is Ideal for AGV Drive Systems?

AGV drive bearings face frequent start-stop cycles, shock loads, and sometimes high warehouse temperatures, making C3 the optimal choice. CN works for AGV auxiliary wheels or light-load rollers, where shock is minimal and temperature stays under 50℃. A 2023 AGV manufacturer report shows that using C3 6205 bearings in heavy-duty steering wheels increased mean time between failures (MTBF) by 28% compared to CN group parts.

How to Calculate Exact Radial Clearance for Custom AGV Applications?

First confirm the bearing’s inner diameter, then match it to the required clearance group. For a 6206 bearing (30mm inner diameter), CN clearance is 0.03mm–0.06mm, while C3 is 0.06mm–0.09mm. If the AGV operates in environments over 60℃, add 0.01mm to the calculated clearance to compensate for thermal expansion, preventing bearing seizure. This adjustment is critical for AGVs in cold storage or high-temperature production facilities.

For project-specific requirements, consult your AGV supplier directly.

What’s the radial clearance tolerance for a 6205 deep groove ball bearing used in AGV load wheels?

A 6205 bearing has a 25mm inner diameter. CN group clearance ranges from 0.020mm to 0.040mm, while C3 group ranges from 0.040mm to 0.065mm. CN is standard for AGV load wheels.

Does high-temperature AGV environments require larger radial clearance?

Yes. When operating temperature exceeds 60℃, select C3 group clearance, which is 0.01mm to 0.02mm larger than CN group for the same bearing size to offset thermal expansion.

Can I adjust radial clearance of deep groove ball bearings during AGV assembly?

No. Deep groove ball bearings have fixed radial clearance per ISO standards. Adjustment post-manufacturing is impossible, so correct clearance selection is mandatory in AGV design.