5311S bearing: complete specifications & equivalents
The 5311S is a ISO 15 radial bearing sized 55 x 120 x 49.2 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 55 mm |
| Outer diameter D | 120 mm |
| Width B | 49.2 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 95 kN |
| Basic static load rating C0 | 73 kN |
| Fatigue load limit Pu | 4.5 kN |
| Limiting speed (mechanical) | 3800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 2400 g |
| Manufacturer designation | NTN 5311S |
| 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 & 5300S-series range
| Bore d | 2.165 in |
|---|---|
| Outer diameter D | 4.724 in |
| Width B | 1.937 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 32.5 mm |
| Smallest bore in 5300S-series | 15 mm |
| Largest outer diameter in 5300S-series | 150 mm |
| Width range across 5300S-series | 19–63.5 mm |
| Bore position in 5300S-series (smallest first) | 10 of 13 |
| Bore above smallest 5300S-series size | 40 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 5311S model number is decoded
NTN 5311S belongs to the heavy-duty 5300S double-row family: the catalogue boundary dimensions read 55 / 120 / 49.2 mm (bore / OD / width). Decoding 5311S: 53 is the double-row dimension series (heavy-duty 5300S double-row family), with 11 encodes the 55 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. Catalogue mass is about 2400 g, which at this 32.5 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. A 55 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted.
Typical equipment & failure modes
Common applications
- electric motor shafts with axial locating duty
- conveyor drive and tension-drum shafts
- agricultural gearbox and PTO shaft supports
- printing-press cylinder and folder shafts
Known failure patterns
- false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch
- thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear
- machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface
- current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways
- current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways
Selection pitfalls — read before you substitute
- In this size class the common miss is lubrication interval, not fit — a 55 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.
- The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.
- Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.
- Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.
- If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.
- The 95/73 kN ratings and 4.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5311S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive.
Frequently asked questions
What are the dimensions and catalogue ratings of NTN 5311S?
5311S is a double-row angular contact ball bearing to ISO 15: 55 mm bore, 120 mm outside diameter, 49.2 mm width (2.165 x 4.724 x 1.937 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 95 kN, C0 73 kN and a 4.5 kN fatigue load limit Pu; the grease limiting speed is 3,800 r/min and the oil rating 5,000 r/min; mass about 2400 g.
How is the 5311S designation structured?
53 is the double-row dimension series (heavy-duty 5300S double-row family); 11 encodes the 55 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 120 mm OD and 49.2 mm width follow the ISO 15 boundary-dimension plan for that series.
Which axial direction does 5311S support?
5311S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope.
What lubrication speeds does NTN print for 5311S?
Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,800 r/min and the oil rating 5,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit.
What should be checked before substituting another make for 5311S?
The 55/120/49.2 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 95 kN / C0 73 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive.
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.