61928-NTN bearing: complete specifications & equivalents

The 61928-NTN is a ISO 15 radial bearing sized 140 x 190 x 24 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 = 190 mm d = 140 B = 24 mm side section front view
Principal dimensions: bore d 140 mm, outer diameter D 190 mm, width B 24 mm. Schematic, not to scale.

Specification table

ParameterValue
Brand NTN
Bore diameter d 140 mm
Outer diameter D 190 mm
Width B 24 mm
Material GCr15
Seal / shield open
Internal clearance CN
Tolerance class P0
Cage steel, stamped ribbon (J-type)
Basic dynamic load rating C 74 kN
Basic static load rating C0 71.5 kN
Fatigue load limit Pu 3.7 kN
Limiting speed (mechanical) 3200 rpm
Operating temperature -40 to +120 °C
Mass 1620 g
Manufacturer designation 6928
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 & 61900-series range

Bore d5.512 in
Outer diameter D7.48 in
Width B0.945 in
ISO bore code28
Radial section height (D−d)/225 mm
Smallest bore in 61900-series3 mm
Largest outer diameter in 61900-series1120 mm
Width range across 61900-series3–118 mm
Bore position in 61900-series (smallest first)33 of 63
Bore above smallest 61900-series size137 mm

Cross references & equivalents

Equivalent modelBrandMatch levelNote
61928-RSR NSK partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 140×190×24 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61928-ZZ NSK partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 140×190×24 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61928-NSK NSK full
Dimensions and internal design equivalent — standard interchange.
Same 140×190×24 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61928 SKF partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 140×190×24 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting.
61928-MA SKF partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 140×190×24 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 61928-NTN model number is decoded

In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61928 carries bore code 28 = 140 mm. Outside diameter 190 mm and width 24 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 140 mm shaft, typical catalogue practice is a m6 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).

Typical equipment & failure modes

Common applications

  • robotics and automation joints
  • lay shafts and idler shafts
  • textile machinery
  • packaging machinery

Known failure patterns

  • contamination wear from dust and dirt ingress through the open arrangement
  • lubricant starvation when no regreasing interval is maintained
  • false brinelling from vibration while the shaft is stationary
  • fretting corrosion on a loose shaft seat

Selection pitfalls — read before you substitute

  • Mount this 140 mm bore bearing by heating the inner ring (induction heater, max 120 °C) — never drive it home through the outer ring or balls, that brinells the raceways.
  • The 619xx thin section at 140 mm bore (25.0 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.
  • The open 61928-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 140×190×24 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
  • Open bearings tolerate the highest speeds in the 61900-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61928 units.
  • A 140 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.
  • Suffixes stack in a defined order — clearance follows the seal code, e.g. 61928-NTN-C3. No clearance suffix means normal CN clearance.
  • The open 61928 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.
  • The 140 mm bore places 61928 at the lower end of NTN's large-size range; at these diameters the pressed-steel cage is speed-limited and NTN commonly supplies a machined brass cage (suffix M) as an option. Verify cage material and relubrication interval with the NTN distributor, and do not extrapolate small-bore speed ratings to this size.
  • NTN lists the grease limiting speed at 3200 r/min for 61928; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.
  • At 74 kN dynamic load rating (C) and 71.5 kN static (C0), 3.7 kN fatigue load limit Cu, 61928 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.
  • At 1620 g (1.6 kg), 61928 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.
  • The 140×190×24 mm envelope of 61928 gives a D/d ratio of 1.36 and only 25.0 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 74/71.5 kN load ratings, 3.7 kN fatigue load limit Cu NTN lists the grease limiting speed at 3200 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 1620 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6928 on the 140×190×24 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61928 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.
  • Order the C3 internal-clearance version (61928 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.

Frequently asked questions

What are the dimensions of a 61928-NTN bearing?

A 61928-NTN deep-groove ball bearing has a 140 mm bore, 190 mm outer diameter and 24 mm width (5.512 × 7.48 × 0.945 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields.

How does the 61900 compare with other series at the same 140 mm bore?

619 is a thin section one step above 618: 190×24 mm with a 25.0 mm radial section at 140 mm bore; a 6228 on the same bore is substantially larger and more heavily rated.

Are 61928 bearings from different brands interchangeable?

For boundary dimensions, yes: every brand's 61928 uses the same ISO 15 envelope (140×190×24 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting.

What is the NTN order number for an open 61928?

NTN lists the open 61928 under the bare designation 6928; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 140 mm bore envelope.

Is 6928 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.