NN3028 bearing: complete specifications & equivalents
The NN3028 is a ISO 15 radial bearing sized 140 x 210 x 53 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 140 mm |
| Outer diameter D | 210 mm |
| Width B | 53 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 330 kN |
| Basic static load rating C0 | 515 kN |
| Fatigue load limit Pu | 53 kN |
| Limiting speed (mechanical) | 2800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 6440 g |
| Manufacturer designation | NTN NN3028 |
| Standard | ISO 15 |
| Catalog version | NTN Ball and Roller Bearings CAT.No.2203E |
| Last verified | 2026-10-01 |
Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203E) · extracted 2026-10-01
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203E); 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 & NN3000-series range
| Bore d | 5.512 in |
|---|---|
| Outer diameter D | 8.268 in |
| Width B | 2.087 in |
| ISO bore code | 28 |
| Radial section height (D−d)/2 | 35 mm |
| Smallest bore in NN3000-series | 25 mm |
| Largest outer diameter in NN3000-series | 680 mm |
| Width range across NN3000-series | 16–163 mm |
| Bore position in NN3000-series (smallest first) | 21 of 40 |
| Bore above smallest NN3000-series size | 115 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NN3028 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; brand-specific OEM equivalents (NSK/FAG/NTN) pending multi-source data. |
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 NN3028 model number is decoded
NN3028 is an NTN NN cylindrical roller bearing: two integral ribs on the outer ring and a ribless, separable inner ring — a non-locating bearing that lets the shaft float axially, inside the 140×210×53 mm ISO 15 envelope. Reading the code: NN for the double-row precision type, then the ISO 15 diameter/width series and the bore code — ×5 = 140 mm (00–03 use the 10/12/15/17 exception table). Double-row NN precision cylindrical roller bearing: ribbed inner ring with a separable outer ring, two roller rows for high radial stiffness on machine-tool spindles; precision classes P5/P4/P2 and clearance are ordered separately. Equivalent-load planning treats NN3028 as a pure radial bearing: keep P below 330 kN at the required L10, and let a paired angular-contact or thrust part carry any sustained axial component. Mount the separable inner ring + roller assembly on the shaft first and slide the outer ring into the housing; never press the outer ring through the rollers of NN3028.
Typical equipment & failure modes
Common applications
- machine-tool main spindles requiring high radial stiffness
- precision gearbox and indexing-drive shafts
- high-rpm motorised grinding and milling spindles
- CNC lathe and machining-centre spindle radial sets
Known failure patterns
- roller smearing (microwelding) at start-up before the oil film builds under insufficient radial load
- cage wear accelerated when the EA high-capacity roller complement runs continuously above its thermal balance
- micro-pitting when the EHL film falls below the composite roughness at high specific load
- false brinelling on standby machines exposed to external vibration
- fretting corrosion on a loose rotating shaft seat
Selection pitfalls — read before you substitute
- At 140 mm bore, oil-lubricated arrangements toward 3,300 r/min need positive flow and drain design; the 6440 g NN3028 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Grease limiting speed 2,800 r/min and oil 3,300 r/min are different limits for NN3028: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- The NN rib arrangement is not interchangeable with another prefix on the same 140 mm seat: double row, ribbed inner ring, separable outer. Swapping NU for NJ changes axial location behaviour even though the 210×53 mm envelope matches.
- Double-row NN precision bearings are typically ordered P5/P4 with specific radial clearance for spindle preloading; a P0/CN NN3028 does not substitute a precision-class execution.
- The 53 mm width and abutment faces must be square to the axis; a tilted spacer concentrates load across the roller set and shows as uneven raceway polish on the 140 mm inner ring.
- The 330/515 kN ratings, 53 kN Pu and 6440 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NN3028 (standard execution); other makes sharing the ISO 15 envelope revise internal geometry without changing the order number, so keep the 2203E reference with the specification for critical drives.
Frequently asked questions
What are the dimensions and catalogue data of NN3028?
NN3028 is an NTN NN double-row precision cylindrical roller bearing to ISO 15: 140 mm bore, 210 mm OD and 53 mm width (5.512 × 8.268 × 2.087 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 330 kN, C0 515 kN, Pu 53 kN, grease limiting speed 2,800 r/min, oil 3,300 r/min, mass about 6440 g. It is open, with a machined or stamped steel cage per the precision execution.
What is the difference between NU, NJ, NUP, N and NF cylindrical roller bearings?
NN and NNU are double-row precision designs rather than single-row rib variants: NN has a ribbed inner ring and separable outer ring, NNU the reverse; both give high radial stiffness for spindles and are commonly ordered with P5/P4 precision and a K 1:12 tapered bore for preload setting. NN3028 is the NN execution.
What do the EA, E and ＊ suffixes mean on NTN cylindrical roller bearings?
EA is NTN's high-capacity design with a pressed sheet-steel cage and optimised roller complement in the same ISO 15 envelope; E marks the high-capacity design at the larger bores; the ＊ symbol printed before the code in the NTN catalogue marks the ULTAGE new-generation specification and is not typed as part of the order number. NN3028 is supplied in the standard open execution shown in the table.
What does the K tapered bore mean on a precision NN bearing like NN3028?
NN3028 has a cylindrical bore and mounts on a plain machined shaft seat; a K execution (1:12 taper) exists in the NN3000 series when preload must be set by drive-up on a tapered seat.
What speeds and lubrication apply to NN3028?
NTN rates NN3028 at 2,800 r/min with grease and 3,300 r/min with oil. The grease figure is the cage/film mechanical ceiling; the oil figure assumes circulating or carefully supplied oil that removes heat from the line-contact zone.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN Ball and Roller Bearings CAT.No.2203E on 2026-10-01. Read our editorial & correction policy.