33112-NTN bearing: complete specifications & equivalents
The 33112-NTN is a ISO 355 radial bearing sized 60 x 100 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 | 60 mm |
| Outer diameter D | 100 mm |
| Width B | 30 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 126 kN |
| Basic static load rating C0 | 164 kN |
| Limiting speed (mechanical) | 3600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 913 g |
| Manufacturer designation | NTN 33112 |
| 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 & 33100-series range
| Bore d | 2.362 in |
|---|---|
| Outer diameter D | 3.937 in |
| Width B | 1.181 in |
| ISO bore code | 12 |
| Radial section height (D−d)/2 | 20 mm |
| Smallest bore in 33100-series | 40 mm |
| Largest outer diameter in 33100-series | 200 mm |
| Width range across 33100-series | 26–62 mm |
| Bore position in 33100-series (smallest first) | 5 of 13 |
| Bore above smallest 33100-series size | 20 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 33112 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 60×100×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
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 33112-NTN model number is decoded
33112 is a metric single-row tapered roller bearing in the NTN 4T programme: a pressed-steel cage guides profiled rollers between a separable cone and cup on the 60×100 mm ISO 355 envelope, with 30 mm overall assembled width T. Digit by digit, the bare number identifies the light-wide 33100 family and a bore code resolving to 60 mm; 100 mm OD and 30 mm assembled T are the matching ISO 355 boundary dimensions shared with other makers of the same dimension series. At 126 kN C the bearing offers about 2.1 kN of dynamic capacity per millimetre of the 60 mm bore — compare any substitution on this ratio and the 30 mm assembled T, not on bore alone. Selection: C 126 kN against C0 164 kN gives a C0/C ratio of 1.30 for the 60 mm bore, and the equivalent combined load must keep below the rating at the target L10 with the pair counted as one unit. Mount the 60 mm-bore cone on the shaft first (induction heat, max 120 °C), fit the cup square in its housing, then set preload or end play; never drive the cup home through the rollers of 33112.
Typical equipment & failure modes
Common applications
- paper-machine press-section rolls
- large agricultural and forestry machine axles
- heavy industrial gearboxes and crane travel drives
- rolling-mill auxiliary and pinion-stand shafts
Known failure patterns
- cone-raceway spalling at the large rib when preload is set too high for the lubricant film
- 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
- pressed-steel cage pocket wear from roller skid at light radial load and high speed
- brinell marks on cone and cup raceways from impact during handling or hammering during fitting
Selection pitfalls — read before you substitute
- Mount the 60 mm cone by induction heating (max 120 °C) and the cup with a press sleeve; the 913 g ring mass makes cocking during fitting a direct raceway-brinelling risk.
- The light-wide 33100 family at 60 mm bore (100×30 mm assembled) carries more capacity than the lighter 320/329 sections but generates more preload heat; confirm oil availability before running near the 4,700 r/min oil ceiling.
- On slash-size and T-code bearings confirm the full code on both cone and cup before fitting: the 60 mm bore alone does not identify the cup, and a mismatched cone/cup set has no catalogue rating.
- On slash-size and T-code bearings confirm the full code on both cone and cup before fitting: the 60 mm bore alone does not identify the cup, and a mismatched cone/cup set has no catalogue rating.
- Open 33112 units have no seals: a wheel-hub or gearbox application needs external sealing or the 3,600 r/min grease figure is meaningless once water reaches the cone rib.
- The 126/164 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 33112 (ISO 355 3CE); 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 33112?
33112 is a metric 4T tapered roller bearing to ISO 355: 60 mm bore, 100 mm outside diameter and 30 mm assembled width T (2.362 × 3.937 × 1.181 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 126 kN, C0 164 kN (2203E prints no Pu for this size), grease limiting speed 3,600 r/min, oil speed 4,700 r/min, mass about 913 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 33112?
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 (33112); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 33112 designation encode the 60 mm bore and what is 3CE?
last two digits 12 are the ISO bore code, ×5 = 60 mm (codes 00–03 use the 10/12/15/17 exception table). The 100 mm OD and 30 mm assembled T follow the ISO 355 dimension-series plan. 3CE 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 33112 list two speeds, 3,600 and 4,700 r/min?
The lower figure, 3,600 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 33112 at 4,700 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 33112 mean?
It is the basic open 4T execution — steel cage, adjusted mounting, no seal or feature suffix. NTN uses U for the uprated design, UTG for ULTAGE large-bearing specs, X for the ISO boundary section, and C/CA/D/A for contact-angle or internal-design variants; all are separate order numbers.
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.