61812-RSR-NTN bearing: complete specifications & equivalents

The 61812-RSR-NTN is a ISO 15 radial bearing sized 60 x 78 x 10 mm (bore x OD x width) with RSR 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 = 78 mm d = 60 B = 10 mm side section front view
Principal dimensions: bore d 60 mm, outer diameter D 78 mm, width B 10 mm. Schematic, not to scale.

Specification table

ParameterValue
Brand NTN
Bore diameter d 60 mm
Outer diameter D 78 mm
Width B 10 mm
Material GCr15
Seal / shield RSR
Internal clearance CN
Tolerance class P0
Cage steel, stamped ribbon (J-type)
Basic dynamic load rating C 12.7 kN
Basic static load rating C0 10.6 kN
Fatigue load limit Pu 0.7 kN
Limiting speed (mechanical) 8000 rpm
Operating temperature -40 to +120 °C
Mass 106 g
Manufacturer designation 6812LLB
Standard ISO 15
Catalog version NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)
Last verified 2026-09-25

Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)) · extracted 2026-09-25

Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)); 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 & 61800-series range

Bore d2.362 in
Outer diameter D3.071 in
Width B0.394 in
ISO bore code12
Radial section height (D−d)/29 mm
Smallest bore in 61800-series1 mm
Largest outer diameter in 61800-series1820 mm
Width range across 61800-series1–140 mm
Bore position in 61800-series (smallest first)23 of 74
Bore above smallest 61800-series size59 mm

Cross references & equivalents

Equivalent modelBrandMatch levelNote
61812-2RS-NSK NSK partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61812-RSR-NSK NSK full
Dimensions and internal design equivalent — standard interchange.
Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61812-ZZ NSK partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61812-NSK NSK partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61812 SKF partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61812-2RS SKF partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61812-RSR SKF full
Dimensions and internal design equivalent — standard interchange.
Same 60×78×10 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 61812-RSR-NTN model number is decoded

61812-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 12 by five gives the 60 mm bore; the 78 mm outside diameter and 10 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 60 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6812LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.

Typical equipment & failure modes

Common applications

  • textile machinery
  • packaging machinery
  • space-constrained gearboxes
  • clutch and transmission assemblies

Known failure patterns

  • ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)
  • lip-lubricant starvation if the bearing runs dry for extended periods
  • false brinelling from vibration while the shaft is stationary
  • fretting corrosion on a loose shaft seat

Selection pitfalls — read before you substitute

  • At 60 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61812 against the shaft shoulder while it cools so the ring cannot creep back.
  • Only 9.0 mm of radial section separates bore and OD on the 618xx series at 60 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6212.
  • The low-drag lip of 61812-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.
  • The non-contact lip of 61812-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 60 mm bore position before relying on it as sealed-for-life.
  • A 60 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.
  • Never mix components between two 61812-RSR-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.
  • NTN catalogues this low-friction non-contact seal as 6812LLB (suffix LB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).
  • At 60 mm bore 61812 is in NTN'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 NTN channel if the application sees impact loads.
  • At 8000 r/min the grease limiting speed for 61812 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.
  • NTN rates 61812 at 12.7 kN dynamic (C) and 10.6 kN static (C0), 0.7 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.
  • At 106 g, 61812 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.
  • The 60×78×10 mm envelope of 61812 gives a D/d ratio of 1.30 and only 9.0 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.
  • The 12.7/10.6 kN load ratings, 0.7 kN fatigue load limit Cu NTN lists the grease limiting speed at 8000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 106 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6812LLB on the 60×78×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61812 in a rated drive.
  • Standard catalogue stock of 61812 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.
  • NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61812 is listed.

Frequently asked questions

What are the dimensions of a 61812-RSR-NTN bearing?

A 61812-RSR-NTN deep-groove ball bearing has a 60 mm bore, 78 mm outer diameter and 10 mm width (2.362 × 3.071 × 0.394 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals.

How does the 61812 bore code work?

The last two digits of 61812 are bore code 12, giving 12 × 5 = 60 mm bore. The 78 mm outside diameter and 10 mm width follow the ISO 15 diameter series, not the bore code alone.

What does the RSR suffix on 61812-RSR mean?

RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments.

What is the NTN suffix for a sealed 61812?

NTN uses suffix LLU for the contact rubber seal (catalogue number 6812LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 60×78×10 mm ISO 15 envelope.

Is 6812LLB a current NTN production size?

The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares.

Reviewed & verified by the MPN Base engineering desk against source catalog NTN Ball and Roller Bearings CAT.No.2203-3/E (2024) on 2026-09-25. Read our editorial & correction policy.