NN3020K bearing: complete specifications & equivalents
The NN3020K is a ISO 15 radial bearing sized 100 x 150 x 37 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 100 mm |
| Outer diameter D | 150 mm |
| Width B | 37 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 170 kN |
| Basic static load rating C0 | 256 kN |
| Fatigue load limit Pu | 29.2 kN |
| Limiting speed (mechanical) | 4000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 2190 g |
| Manufacturer designation | NTN NN3020K |
| 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 | 3.937 in |
|---|---|
| Outer diameter D | 5.906 in |
| Width B | 1.457 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 25 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) | 16 of 40 |
| Bore above smallest NN3000-series size | 75 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NN3020K | 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 NN3020K model number is decoded
For pure radial duty on a 100 mm shaft NTN supplies NN3020K: two integral ribs on the outer ring and a ribless, separable inner ring; the open execution is rated 4,000 r/min on grease and 4,800 r/min on oil. On the NTN nameplate NN states which ring carries the ribs, which determines whether NN3020K floats or locates; the numeric remainder is the ISO 15 series and 100 mm bore reference, not a fit or clearance instruction. The separable ring comes off without removing the roller assembly from the other ring, which eases inspection and lets the non-locating arrangement accommodate thermal shaft growth. Selection arithmetic: Pu 29.2 kN is the fatigue load limit feeding the adjusted-life equation, and the C0/C ratio of 1.51 (256/170 kN) shows the high-static-capacity proportioning of this 100 mm bore. Heat the inner ring to max 120 °C for the 100 mm interference fit and support the ring face square during fitting; cocking over a keyway brinells the raceway before first rotation.
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
- roller smearing (microwelding) at start-up before the oil film builds under insufficient radial load
- cage distortion after a mounting blow carried through the roller set
- micro-pitting when the EHL film falls below the composite roughness at high specific load
- brinelling from static overload or impact during handling
- electrical pitting on VFD-driven motor shafts without grounding protection
Selection pitfalls — read before you substitute
- Induction-heat the 100 mm inner ring (max 120 °C) and mount it before fitting the outer ring; the ring mass makes square guidance essential — driving through the rollers brinells the 150 mm raceway.
- The EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 170/256 kN pair here belongs to NN3020K as printed, not to the bare size.
- The 25.0 mm section at 100 mm bore leaves a narrow oil path; with the standard cage the relubrication groove and oil-level design must keep grease from churning in the 37 mm-wide cavity.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 150 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 170/256 kN pair here belongs to NN3020K as printed, not to the bare size.
- The 170/256 kN ratings, 29.2 kN Pu and 2190 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NN3020K (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 NN3020K?
NN3020K is an NTN NN double-row precision cylindrical roller bearing to ISO 15: 100 mm bore, 150 mm OD and 37 mm width (3.937 × 5.906 × 1.457 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 170 kN, C0 256 kN, Pu 29.2 kN, grease limiting speed 4,000 r/min, oil 4,800 r/min, mass about 2190 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. NN3020K 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. NN3020K is supplied in the standard open execution shown in the table.
What does the K tapered bore mean on a precision NN bearing like NN3020K?
The K suffix denotes a 1:12 tapered bore. NN3020K 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 NN3020 execution of the same envelope mounts on a plain seat.
What speeds and lubrication apply to NN3020K?
NTN rates NN3020K at 4,000 r/min with grease and 4,800 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.