30313D bearing: complete specifications & equivalents
The 30313D is a ISO 355 radial bearing sized 65 x 140 x 36 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 65 mm |
| Outer diameter D | 140 mm |
| Width B | 36 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 192 kN |
| Basic static load rating C0 | 204 kN |
| Limiting speed (mechanical) | 2500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 2410 g |
| Manufacturer designation | NTN 30313D |
| Standard | ISO 355 |
| 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 & 30300-series range
| Bore d | 2.559 in |
|---|---|
| Outer diameter D | 5.512 in |
| Width B | 1.417 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 37.5 mm |
| Smallest bore in 30300-series | 15 mm |
| Largest outer diameter in 30300-series | 500 mm |
| Width range across 30300-series | 14.25–105 mm |
| Bore position in 30300-series (smallest first) | 12 of 32 |
| Bore above smallest 30300-series size | 50 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30313D | 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 30313D model number is decoded
30313D is the NTN 4T catalogue entry for a 65×140×36 mm metric tapered roller bearing — separable cone and cup, designed for combined radial and axial load as an individually adjusted bearing. NTN also quotes this bearing with its ISO 355 dimension-series abbreviation, 7GB, which is the maker-neutral cross-reference for the 65×140 mm envelope; 4T is NTN's own tapered-roller brand mark on the parts. The 37.5 mm radial section carries the roller complement across the 65–140 mm envelope; section and contact angle differ between NTN metric families even at the same bore, so 302/322/323 are not drop-in swaps. Imperial cross-check for the drawing: 65×140×36 mm is 2.559 × 5.512 × 1.417 in; ISO 355 makes the envelope interchangeable but C/C0, 192/204 kN, is NTN-specific. Fillet radii must clear the ring chamfers of the 140 mm cup and 65 mm cone; use undercut shoulders so the rings seat fully rather than bridging on a shaft radius.
Typical equipment & failure modes
Common applications
- large conveyor and bucket-elevator pulleys
- mineral-processing feeder and crusher auxiliaries
- marine winch and deck-machinery shafts
- paper-machine press-section rolls
Known failure patterns
- cup creep and housing fretting when the specified outer-ring press fit is not achieved
- flaking on one cone only when a back-to-back / face-to-face pair is loaded unevenly by a bent shaft
- smearing on the roller large ends and cone rib after a dry start with preload but no oil film
- cage damage from a mounting blow delivered through the roller complement instead of the ring face
- false brinelling on a stationary paired set exposed to external vibration
Selection pitfalls — read before you substitute
- Mount the 65 mm cone by induction heating (max 120 °C) and the cup with a press sleeve; the 2410 g ring mass makes cocking during fitting a direct raceway-brinelling risk.
- The steeper contact angle of the large-OD 30300 family with the steeper contact angle raises axial capacity but lowers the speed ceiling against a 302/322 bearing at 65 mm bore; do not swap to the lighter family without re-checking the 2,500 r/min grease limit and the thrust load split.
- Never fit the 65 mm cone by hammering the 140 mm cup: force for both press fits goes through the ring faces only, or brinell marks release as noise within the first running hours.
- Minimum load matters at high speed: an unloaded 30313D at a large fraction of 2,500 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded pair arrangements.
- The U/UTG/X/C/CA/D suffix variants of a base number share the bore but not the article: ordering 30313D by size alone can deliver the wrong contact-angle execution for a pinion position.
- The 192/204 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 30313D (ISO 355 7GB); internal geometry legitimately differs between manufacturers, so re-verify ratings, adjustment and suffix before substituting another make on a rated drive.
Frequently asked questions
What are the dimensions and catalogue ratings of NTN 30313D?
30313D is a metric 4T tapered roller bearing to ISO 355: 65 mm bore, 140 mm outside diameter and 36 mm assembled width T (2.559 × 5.512 × 1.417 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 192 kN, C0 204 kN (2203E prints no Pu for this size), grease limiting speed 2,500 r/min, oil speed 3,300 r/min, mass about 2410 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 30313D?
4T is NTN's tapered roller bearing brand mark, stamped on the cone and cup in the factory. It identifies the NTN 4T programme and is not a dimension, so the catalogue and this page list the bare ISO 355 number (30313D); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 30313D designation encode the 65 mm bore and what is 7GB?
last two digits 13 are the ISO bore code, ×5 = 65 mm (codes 00–03 use the 10/12/15/17 exception table). The 140 mm OD and 36 mm assembled T follow the ISO 355 dimension-series plan. 7GB is the maker-neutral ISO 355 abbreviation for this dimension series (the same code other manufacturers print); 4T is NTN's own brand mark.
Why does 30313D list two speeds, 2,500 and 3,300 r/min?
The lower figure, 2,500 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 30313D at 3,300 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 30313D mean?
Suffix reading on 30313D: the trailing A/C/D (or E1) letter marks an NTN contact-angle or internal-design revision of the base number, not a seal or clearance code; the suffix is part of the order number and the variants are not interchangeable articles.
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.