NN3044K bearing: complete specifications & equivalents
The NN3044K is a ISO 15 radial bearing sized 220 x 340 x 90 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 220 mm |
| Outer diameter D | 340 mm |
| Width B | 90 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 905 kN |
| Basic static load rating C0 | 1480 kN |
| Fatigue load limit Pu | 132 kN |
| Limiting speed (mechanical) | 1700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 28200 g |
| Manufacturer designation | NTN NN3044K |
| 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 | 8.661 in |
|---|---|
| Outer diameter D | 13.386 in |
| Width B | 3.543 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 60 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) | 28 of 40 |
| Bore above smallest NN3000-series size | 195 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NN3044K | 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 NN3044K model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, NN3044K appears as a 220 mm bore single-row cylindrical roller bearing (905 kN C / 1480 kN C0) with a machined or stamped steel cage per the precision execution, listed to the ISO 15 boundary plan. Digit by digit, NN3044K reads as NN (double row, ribbed inner ring, separable outer), ISO 15 series, and bore 220 mm; trailing letters such as EA or E mark the cage/capacity execution and are part of the order number. The roller-set pitch sits inside the 60.0 mm radial section between the 220 mm bore and 340 mm OD; NTN prints Fw/Ew raceway diameters only for selected executions. Selection arithmetic: Pu 132 kN is the fatigue load limit feeding the adjusted-life equation, and the C0/C ratio of 1.64 (1480/905 kN) shows the high-static-capacity proportioning of this 220 mm bore. After mounting verify the outer ring slides axially by hand at ambient temperature; a stuck float ring in a NN3044K non-locating position preloads the bearing when the shaft grows.
Typical equipment & failure modes
Common applications
- high-rpm motorised grinding and milling spindles
- CNC lathe and machining-centre spindle radial sets
- precision rotary-table and dividing-head bearings
- high-speed turbine and turbo-blower rotor supports
Known failure patterns
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- pressed-steel cage pocket wear when rollers skid at light load or too-thin lubricant
- grease starvation and cage drag when relubrication intervals are extended past the grease life
- brinelling from static overload or impact during handling
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
Selection pitfalls — read before you substitute
- At 220 mm bore, oil-lubricated arrangements toward 2,100 r/min need positive flow and drain design; the 28200 g NN3044K ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Grease limiting speed 1,700 r/min and oil 2,100 r/min are different limits for NN3044K: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 340 mm race brinells and releases as vibration within hours.
- The EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 905/1480 kN pair here belongs to NN3044K as printed, not to the bare size.
- The NN rib arrangement is not interchangeable with another prefix on the same 220 mm seat: double row, ribbed inner ring, separable outer. Swapping NU for NJ changes axial location behaviour even though the 340×90 mm envelope matches.
- The 905/1480 kN ratings, 132 kN Pu and 28200 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NN3044K (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 NN3044K?
NN3044K is an NTN NN double-row precision cylindrical roller bearing to ISO 15: 220 mm bore, 340 mm OD and 90 mm width (8.661 × 13.386 × 3.543 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 905 kN, C0 1480 kN, Pu 132 kN, grease limiting speed 1,700 r/min, oil 2,100 r/min, mass about 28200 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. NN3044K 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. NN3044K is supplied in the standard open execution shown in the table.
What does the K tapered bore mean on a precision NN bearing like NN3044K?
The K suffix denotes a 1:12 tapered bore. NN3044K mounts on a tapered shaft seat or adapter sleeve and is driven up to a measured residual clearance or preload — this is how precision spindle bearings achieve stiffness without locknut guesswork; the cylindrical-bore NN3044 execution of the same envelope mounts on a plain seat.
What speeds and lubrication apply to NN3044K?
NTN rates NN3044K at 1,700 r/min with grease and 2,100 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.