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.

Bearing dimension schematic Front view shows outer diameter D and bore d; side section shows width B. D = 90 mm d = 55 B = 18 mm side section front view
Principal dimensions: bore d 55 mm, outer diameter D 90 mm, width B 18 mm. Schematic, not to scale.

Specification table

ParameterValue
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 d2.165 in
Outer diameter D3.543 in
Width B0.709 in
ISO bore code11
Radial section height (D−d)/217.5 mm
Smallest bore in 6000-series4 mm
Largest outer diameter in 6000-series1150 mm
Width range across 6000-series4–155 mm
Bore position in 6000-series (smallest first)18 of 61
Bore above smallest 6000-series size51 mm

Cross references & equivalents

Equivalent modelBrandMatch levelNote
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.