6011-2RS-NSK bearing: complete specifications & equivalents
The 6011-2RS-NSK is a ISO 15 radial bearing sized 55 x 90 x 18 mm (bore x OD x width) with 2RS sealing. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NSK |
| Bore diameter d | 55 mm |
| Outer diameter D | 90 mm |
| Width B | 18 mm |
| Material | GCr15 |
| Seal / shield | 2RS |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 31 kN |
| Basic static load rating C0 | 21.2 kN |
| Operating temperature | -40 to +150 °C |
| Mass | 381 g |
| Manufacturer designation | NSK 6011DDU |
| Standard | ISO 15 |
| Catalog version | NSK Rolling Bearings E1103 Part C |
| Last verified | 2026-09-24 |
Source: catalog reference (NSK Rolling Bearings E1103 Part C) · extracted 2026-09-24
Dimensions in inches & 6000-series range
| Bore d | 2.165 in |
|---|---|
| Outer diameter D | 3.543 in |
| Width B | 0.709 in |
| ISO bore code | 11 |
| Radial section height (D−d)/2 | 17.5 mm |
| Smallest bore in 6000-series | 4 mm |
| Largest outer diameter in 6000-series | 1150 mm |
| Width range across 6000-series | 4–155 mm |
| Bore position in 6000-series (smallest first) | 18 of 61 |
| Bore above smallest 6000-series size | 51 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6011-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6011-2RS-FAG | FAG | full Dimensions and internal design equivalent — standard interchange. | Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6011-ZZ-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6011-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6011-2RS-NTN | NTN | full Dimensions and internal design equivalent — standard interchange. | Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6011-RSR-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6011-ZZ-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6011 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6011-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6011-2RS | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6011-M | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating 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 6011-2RS-NSK model number is decoded
In the 6000-series (diameter series 0 of ISO 15) the last two digits encode the bore: 6011 carries bore code 11 = 55 mm. Outside diameter 90 mm and width 18 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 55 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NSK's contact-seal catalogue number is 6011DDU (suffix DDU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.
Typical equipment & failure modes
Common applications
- industrial fans
- industrial electric motors
- centrifugal and positive-displacement pumps
- gearboxes and speed reducers
Known failure patterns
- seal-lip hardening and loss of pre-grease in sustained high-temperature service
- grease-life expiry in the sealed-for-life cavity (no relubrication path)
- cage damage from operation beyond the limiting speed
- electrical pitting in VFD-driven motors without grounding protection
Selection pitfalls — read before you substitute
- At 55 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6011 against the shaft shoulder while it cools so the ring cannot creep back.
- The 60xx extra-light section at 55 mm bore uses a smaller 90 mm OD than a 6211; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.
- Contact seals add drag and heat: 6011-2RS-NSK runs slower and cooler-limited than the open 6011; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.
- Never wash a sealed 6011-2RS-NSK in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.
- Do not quieten a noisy bearing by preloading it: the 6000-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.
- The housing bore for the 90 mm OD should be round within IT7; an oval bore pinches the outer ring of 6011-2RS-NSK and shows up later as two-point loaded raceway wear.
- NSK catalogues the contact-sealed version as 6011DDU (suffix DDU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing. NSK's DDU lip design is single-lip contact, so grease life is longer than VV but drag torque is higher.
- At 55 mm bore 6011 is in NSK's upper general-purpose range; the pressed-steel cage is standard, but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NSK channel if the application sees impact loads.
- At 31 kN dynamic load rating (C) and 21.2 kN static (C0), 6011 is a medium-load NSK bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NSK catalogue.
- At 381 g, 6011 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.
- The 55×90×18 mm envelope of 6011 gives a D/d ratio of 1.64 and 17.5 mm radial section height — this NSK thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.
- The 31/21.2 kN load ratings, mass 381 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6011DDU on the 55×90×18 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6011 in a rated drive. NSK does not tabulate reference or limiting speeds in the E1103 Part C dimension tables used for this page — consult NSK's separate speed-rating tables before high-speed service.
- When replacing a failed unit, inspect the shaft and housing seats before fitting the new 6011 — a new bearing pressed onto a worn or oval seat reproduces the original failure mode in a fraction of its expected life.
- NSK's VV non-contact seal keeps frictional torque close to the open 6011; in motor duty where heat build-up matters, VV is the usual compromise between debris protection and speed capability.
Frequently asked questions
What are the dimensions of a 6011-2RS-NSK bearing?
A 6011-2RS-NSK deep-groove ball bearing has a 55 mm bore, 90 mm outer diameter and 18 mm width (2.165 × 3.543 × 0.709 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased.
What lubrication does 6011-2RS-NSK need?
6011-2RS-NSK is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6011 with a housing grease fitting instead.
How does the 6011 bore code work?
The last two digits of 6011 are bore code 11, giving 11 × 5 = 55 mm bore. The 90 mm outside diameter and 18 mm width follow the ISO 15 diameter series, not the bore code alone.
What is the NSK suffix for a sealed 6011?
NSK uses suffix DDU for the contact rubber seal (catalogue number 6011DDU), VV for the non-contact rubber seal, and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NSK suffixes while keeping the 55×90×18 mm ISO 15 envelope.
Does the manufacturing plant affect 6011DDU?
NSK produces standard deep-groove sizes in several plants worldwide to the same drawing; the origin on the box label does not change the ISO 15 envelope or the E1103 catalogue ratings quoted here.
Reviewed & verified by the MPN Base engineering desk against source catalog NSK Rolling Bearings E1103 Part C on 2026-09-24. Read our editorial & correction policy.