6052-NTN bearing: complete specifications & equivalents
The 6052-NTN is a ISO 15 radial bearing sized 260 x 400 x 65 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 260 mm |
| Outer diameter D | 400 mm |
| Width B | 65 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 325 kN |
| Basic static load rating C0 | 375 kN |
| Fatigue load limit Pu | 15.1 kN |
| Limiting speed (mechanical) | 1500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 25000 g |
| Manufacturer designation | 6052 |
| Standard | ISO 15 |
| Catalog version | NTN Ball and Roller Bearings CAT.No.2203-3/E (2024) |
| Last verified | 2026-09-25 |
Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)) · extracted 2026-09-25
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)); NTN® is a trademark of NTN Corporation, used here for identification only — mpnbase is not an authorized NTN distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at ntnglobal.com.
Dimensions in inches & 6000-series range
| Bore d | 10.236 in |
|---|---|
| Outer diameter D | 15.748 in |
| Width B | 2.559 in |
| ISO bore code | 52 |
| Radial section height (D−d)/2 | 70 mm |
| Smallest bore in 6000-series | 4 mm |
| Largest outer diameter in 6000-series | 1150 mm |
| Width range across 6000-series | 4–155 mm |
| Bore position in 6000-series (smallest first) | 41 of 61 |
| Bore above smallest 6000-series size | 256 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6052 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 260×400×65 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6052-M | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 260×400×65 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
How the 6052-NTN model number is decoded
In the 6000-series (diameter series 0 of ISO 15) the last two digits encode the bore: 6052 carries bore code 52 = 260 mm. Outside diameter 400 mm and width 65 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 260 mm shaft, typical catalogue practice is a m6 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).
Typical equipment & failure modes
Common applications
- medium and heavy industrial drives
- large gearboxes
- industrial fans and blowers
- hoists and winches
Known failure patterns
- contamination wear from dust and dirt ingress through the open arrangement
- lubricant starvation when no regreasing interval is maintained
- edge loading from shaft deflection or housing misalignment
- rolling-contact fatigue spalling after the rated L10 life is exceeded
Selection pitfalls — read before you substitute
- Large bores like the 260 mm of 6052-NTN demand clean, burr-free seats; one raised burr under a ring this size cocks the bearing and concentrates load at the raceway edge, cutting life drastically.
- The 60xx extra-light section at 260 mm bore uses a smaller 400 mm OD than a 6252; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.
- Storage matters for open bearings: 6052-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.
- Open bearings tolerate the highest speeds in the 6000-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6052 units.
- Measure the shaft, do not trust the drawing: a 260 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6052-NTN.
- Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6000-series position can soften the mixture and leak — clean out the old fill before switching grease types.
- The open 6052 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.
- The 260 mm bore places 6052 in NTN's upper large-size range; centrifugal force at this diameter sharply caps the grease limiting speed, so NTN usually supplies a machined brass cage (suffix M) and expects oil lubrication for continuous duty. Confirm relubrication interval and cage material with the NTN distributor.
- NTN lists the grease limiting speed at 1500 r/min for 6052; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.
- NTN rates 6052 at 325 kN dynamic (C) and 375 kN static (C0), 15.1 kN fatigue load limit Cu; this is an upper heavy-load rating where the pressed-steel cage is not recommended — NTN supplies a machined brass cage (suffix M) and the static C0 must be verified against any shock or lifting loads the bearing sees during mounting.
- At 25000 g (25.0 kg), 6052 is a very heavy bearing where handling and mounting method directly affect service life; NTN requires induction heating of the inner ring (max 120 °C), a mechanical puller for removal, and a defined lifting procedure to avoid damaging the machined brass cage.
- The 260×400×65 mm envelope of 6052 gives a D/d ratio of 1.54 and 70.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.
- The 325/375 kN load ratings, 15.1 kN fatigue load limit Cu NTN lists the grease limiting speed at 1500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 25000 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6052 on the 260×400×65 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6052 in a rated drive.
- Order the C3 internal-clearance version (6052 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.
- Standard catalogue stock of 6052 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.
Frequently asked questions
What are the dimensions of a 6052-NTN bearing?
A 6052-NTN deep-groove ball bearing has a 260 mm bore, 400 mm outer diameter and 65 mm width (10.236 × 15.748 × 2.559 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields.
Are 6052 bearings from different brands interchangeable?
For boundary dimensions, yes: every brand's 6052 uses the same ISO 15 envelope (260×400×65 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting.
What internal clearance does 6052-NTN have?
Unless a clearance suffix says otherwise, 6052-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6052 and verify the residual clearance after mounting.
What is the NTN order number for an open 6052?
NTN lists the open 6052 under the bare designation 6052; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 260 mm bore envelope.
Is 6052 a current NTN production size?
The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN Ball and Roller Bearings CAT.No.2203-3/E (2024) on 2026-09-25. Read our editorial & correction policy.