61800-NSK bearing: complete specifications & equivalents

The 61800-NSK is a ISO 15 radial bearing sized 10 x 19 x 5 mm (bore x OD x width). 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 = 19 mm d = 10 B = 5 mm side section front view
Principal dimensions: bore d 10 mm, outer diameter D 19 mm, width B 5 mm. Schematic, not to scale.

Specification table

ParameterValue
Brand NSK
Bore diameter d 10 mm
Outer diameter D 19 mm
Width B 5 mm
Material GCr15
Seal / shield open
Internal clearance CN
Tolerance class P0
Cage steel, stamped ribbon (J-type)
Basic dynamic load rating C 1.89 kN
Basic static load rating C0 0.84 kN
Operating temperature -40 to +150 °C
Mass 5 g
Manufacturer designation NSK 6800
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 & 61800-series range

Bore d0.394 in
Outer diameter D0.748 in
Width B0.197 in
ISO bore code00
Radial section height (D−d)/24.5 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)11 of 74
Bore above smallest 61800-series size9 mm

Cross references & equivalents

Equivalent modelBrandMatch levelNote
61800-FAG FAG full
Dimensions and internal design equivalent — standard interchange.
Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61800-2RS-FAG FAG partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61800-ZZ-FAG FAG partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61800-NTN NTN full
Dimensions and internal design equivalent — standard interchange.
Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61800-2RS-NTN NTN partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61800-RSR-NTN NTN partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61800-ZZ-NTN NTN partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61800 SKF full
Dimensions and internal design equivalent — standard interchange.
Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61800-2RS SKF partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61800-ZZ SKF partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
W61800-2RS SKF partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
W61800-ZZ SKF partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
W61800 SKF partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 10×19×5 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 61800-NSK model number is decoded

In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61800 carries bore code 10 = 10 mm. Outside diameter 19 mm and width 5 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 10 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NSK catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (steel shields), VV (non-contact rubber seals) and DDU (contact rubber seals).

Typical equipment & failure modes

Common applications

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

Known failure patterns

  • contamination wear from dust and dirt ingress through the open arrangement
  • lubricant starvation when no regreasing interval is maintained
  • brinelling from static overload or hammering during mounting
  • false brinelling from vibration while the shaft is stationary

Selection pitfalls — read before you substitute

  • Temperature rise and interference fits consume internal clearance on this 10 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61800 with C3 for those conditions.
  • Only 4.5 mm of radial section separates bore and OD on the 618xx series at 10 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6210.
  • The open 61800-NSK has no lubricant retention: grease escapes and contaminants migrate straight into the 10×19×5 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
  • Storage matters for open bearings: 61800-NSK leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.
  • Measure the shaft, do not trust the drawing: a 10 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 61800-NSK.
  • Deep-groove ball bearings tolerate only minutes of misalignment; if the 19 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61800-NSK.
  • The open 61800 has no integral sealing; in the NSK E1103 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), VV (non-contact rubber seals) and DDU (contact rubber seals). NSK does not offer a low-torque contact seal equivalent to NTN's LLH in this catalogue — for high-speed sealed duty specify the VV non-contact seal and an external housing labyrinth.
  • At 10 mm bore the 61800 sits in NSK's miniature range; NSK ships these sizes with a pressed-steel cage and P0 tolerance as standard, and NSK's EA (extra-precision) or P5 class is a special-order upgrade for spindle duty — do not assume catalogue P0 figures hold for instrument use without an NSK engineering check.
  • At 1.89 kN dynamic load rating (C) and 0.84 kN static (C0), 61800 is a light-load NSK bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.
  • At only 5 g, 61800 is a lightweight NSK bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.
  • The 10×19×5 mm envelope of 61800 gives a D/d ratio of 1.90 and 4.5 mm radial section height — a standard NSK medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to NSK's listed speed ratings, and C3 clearance is the common choice for hot shafts.
  • The 1.89/0.84 kN load ratings, mass 5 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6800 on the 10×19×5 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61800 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.
  • NSK's VV non-contact seal keeps frictional torque close to the open 61800; in motor duty where heat build-up matters, VV is the usual compromise between debris protection and speed capability.
  • NSK supplies its sealed units pre-greased for general duty between roughly -10 and +110 °C; low-temperature, food-grade and high-temperature fills are special executions — ask at order time, because DDU/VV units are not designed to be opened and repacked.

Frequently asked questions

What are the dimensions of a 61800-NSK bearing?

A 61800-NSK deep-groove ball bearing has a 10 mm bore, 19 mm outer diameter and 5 mm width (0.394 × 0.748 × 0.197 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields.

How should 61800-NSK be mounted?

Apply the mounting force to the ring being fitted: on a 10 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 lubrication does 61800-NSK need?

The open 61800-NSK is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval.

What is the NSK order number for an open 61800?

NSK lists the open 61800 under the bare designation 6800; protected versions use suffixes ZZ (steel shields), VV (non-contact rubber seals) and DDU (contact rubber seals) on the same 10 mm bore envelope.

Does NSK offer 61800 with C3 clearance?

NSK lists C3 (and C4) internal-clearance options for most deep-groove sizes under the same base designation; the clearance is fixed at manufacture, so specify it at order time rather than planning to adjust later.

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.