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.
Specification table
| Parameter | Value |
|---|---|
| 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 d | 0.394 in |
|---|---|
| Outer diameter D | 0.748 in |
| Width B | 0.197 in |
| ISO bore code | 00 |
| Radial section height (D−d)/2 | 4.5 mm |
| Smallest bore in 61800-series | 1 mm |
| Largest outer diameter in 61800-series | 1820 mm |
| Width range across 61800-series | 1–140 mm |
| Bore position in 61800-series (smallest first) | 11 of 74 |
| Bore above smallest 61800-series size | 9 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 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.