61810-ZZ-NTN bearing: complete specifications & equivalents

The 61810-ZZ-NTN is a ISO 15 radial bearing sized 50 x 65 x 7 mm (bore x OD x width) with ZZ 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 = 65 mm d = 50 B = 7 mm side section front view
Principal dimensions: bore d 50 mm, outer diameter D 65 mm, width B 7 mm. Schematic, not to scale.

Specification table

ParameterValue
Brand NTN
Bore diameter d 50 mm
Outer diameter D 65 mm
Width B 7 mm
Material GCr15
Seal / shield ZZ
Internal clearance CN
Tolerance class P0
Cage steel, stamped ribbon (J-type)
Basic dynamic load rating C 7.3 kN
Basic static load rating C0 6.1 kN
Fatigue load limit Pu 0.41 kN
Limiting speed (mechanical) 9600 rpm
Operating temperature -40 to +120 °C
Mass 52 g
Manufacturer designation 6810JRZZ
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 d1.969 in
Outer diameter D2.559 in
Width B0.276 in
ISO bore code10
Radial section height (D−d)/27.5 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)21 of 74
Bore above smallest 61800-series size49 mm

Cross references & equivalents

Equivalent modelBrandMatch levelNote
61810-2RS-NSK NSK partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61810-RSR-NSK NSK partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61810-ZZ NSK full
Dimensions and internal design equivalent — standard interchange.
Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61810-NSK NSK partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61810 SKF partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61810-2RS SKF partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61810-RSR SKF partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
W61810-2RS SKF partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 50×65×7 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 61810-ZZ-NTN model number is decoded

In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61810 carries bore code 10 = 50 mm. Outside diameter 65 mm and width 7 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 50 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6810JRZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.

Typical equipment & failure modes

Common applications

  • clutch and transmission assemblies
  • robotics and automation joints
  • lay shafts and idler shafts
  • textile machinery

Known failure patterns

  • fine-particle abrasion when non-contact shields let dust past in dirty duty
  • grease aging in the shield-for-life cavity with no relubrication path
  • false brinelling from vibration while the shaft is stationary
  • fretting corrosion on a loose shaft seat

Selection pitfalls — read before you substitute

  • At 50 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61810 against the shaft shoulder while it cools so the ring cannot creep back.
  • The 618xx thin section at 50 mm bore has only a 7.5 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6210.
  • ZZ shields are non-contact: 61810-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61810-2RS for that.
  • Do not wash 61810-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.
  • Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.
  • The housing bore for the 65 mm OD should be round within IT7; an oval bore pinches the outer ring of 61810-ZZ-NTN and shows up later as two-point loaded raceway wear.
  • NTN catalogues the shielded version as 6810JRZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.
  • The 50 mm bore puts 61810 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.
  • At 9600 r/min the grease limiting speed for 61810 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.
  • NTN rates 61810 at 7.3 kN dynamic (C) and 6.1 kN static (C0), 0.41 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 52 g, 61810 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 50×65×7 mm envelope of 61810 gives a D/d ratio of 1.30 and only 7.5 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 7.3/6.1 kN load ratings, 0.41 kN fatigue load limit Cu NTN lists the grease limiting speed at 9600 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 52 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6810JRZZ on the 50×65×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61810 in a rated drive.
  • NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.
  • Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.

Frequently asked questions

What are the dimensions of a 61810-ZZ-NTN bearing?

A 61810-ZZ-NTN deep-groove ball bearing has a 50 mm bore, 65 mm outer diameter and 7 mm width (1.969 × 2.559 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields.

What internal clearance does 61810-ZZ-NTN have?

Unless a clearance suffix says otherwise, 61810-ZZ-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61810 and verify the residual clearance after mounting.

How should 61810-ZZ-NTN be mounted?

Apply the mounting force to the ring being fitted: on a 50 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals.

What is the NTN suffix for a sealed 61810?

NTN uses suffix LLU for the contact rubber seal (catalogue number 6810JRZZ), 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 50×65×7 mm ISO 15 envelope.

Is 6810JRZZ 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.