NN3015K bearing: complete specifications & equivalents
The NN3015K is a ISO 15 radial bearing sized 75 x 115 x 30 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 75 mm |
| Outer diameter D | 115 mm |
| Width B | 30 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 107 kN |
| Basic static load rating C0 | 149 kN |
| Fatigue load limit Pu | 18.2 kN |
| Limiting speed (mechanical) | 5400 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1110 g |
| Manufacturer designation | NTN NN3015K |
| 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 | 2.953 in |
|---|---|
| Outer diameter D | 4.528 in |
| Width B | 1.181 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 20 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) | 11 of 40 |
| Bore above smallest NN3000-series size | 50 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NN3015K | 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 NN3015K model number is decoded
NN3015K is the standard section of the NTN NN3000 dimension series for a 75 mm shaft — 107 kN of basic dynamic capacity in a 1110 g, open bearing. Numbering ties NN3015K to its envelope: type code NN, series NN3000, 75 mm bore; the 115×30 mm outline therefore swaps dimensionally with other ISO 15 bearings of the same code, though rib arrangements differ by prefix. Line contact between rollers and raceways gives NN3015K high radial capacity but no tolerance for misalignment: beyond roughly 3–4 arc-minutes the roller ends edge-load and fatigue accelerates. Mass 1110 g for the 75×115×30 mm NN3015K execution covers the pressed-steel cage and full roller complement; substitute on mass plus rating, not envelope alone. On NN arrangements confirm which ring is separable before heating: forcing the ribbed ring off over the roller complement damages the cage and rib faces.
Typical equipment & failure modes
Common applications
- precision gearbox and indexing-drive shafts
- high-rpm motorised grinding and milling spindles
- CNC lathe and machining-centre spindle radial sets
- precision rotary-table and dividing-head bearings
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
- grease starvation and cage drag when relubrication intervals are extended past the grease life
- hard-particle indentation of raceways in unfiltered oil or open arrangements
- electrical pitting on VFD-driven motor shafts without grounding protection
Selection pitfalls — read before you substitute
- Induction-heat the 75 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 115 mm raceway.
- The 20.0 mm section at 75 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 30 mm-wide cavity.
- Wide (22/23) and light (10/49) executions at 75 mm bore share bore but not OD/width; check the full NN3000 series code before substituting, because housing and shoulder geometry will not interchange.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NN3015K skids at 5,400 r/min and fails by smearing long before L10 fatigue.
- Wide (22/23) and light (10/49) executions at 75 mm bore share bore but not OD/width; check the full NN3000 series code before substituting, because housing and shoulder geometry will not interchange.
- The 107/149 kN ratings, 18.2 kN Pu and 1110 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NN3015K (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 NN3015K?
NN3015K is an NTN NN double-row precision cylindrical roller bearing to ISO 15: 75 mm bore, 115 mm OD and 30 mm width (2.953 × 4.528 × 1.181 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 107 kN, C0 149 kN, Pu 18.2 kN, grease limiting speed 5,400 r/min, oil 6,300 r/min, mass about 1110 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. NN3015K 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. NN3015K is supplied in the standard open execution shown in the table.
What does the K tapered bore mean on a precision NN bearing like NN3015K?
The K suffix denotes a 1:12 tapered bore. NN3015K 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 NN3015 execution of the same envelope mounts on a plain seat.
What speeds and lubrication apply to NN3015K?
NTN rates NN3015K at 5,400 r/min with grease and 6,300 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.