61980 bearing: complete specifications & equivalents

The 61980 is a ISO 15 radial bearing sized 400 x 540 x 65 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 = 540 mm d = 400 B = 65 mm side section front view
Principal dimensions: bore d 400 mm, outer diameter D 540 mm, width B 65 mm. Schematic, not to scale.

Specification table

ParameterValue
Brand NTN
Bore diameter d 400 mm
Outer diameter D 540 mm
Width B 65 mm
Material GCr15
Seal / shield open
Internal clearance CN
Tolerance class P0
Cage steel, stamped ribbon (J-type)
Basic dynamic load rating C 370 kN
Basic static load rating C0 535 kN
Fatigue load limit Pu 16.4 kN
Limiting speed (mechanical) 990 rpm
Operating temperature -40 to +120 °C
Mass 41600 g
Manufacturer designation 6980
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 d15.748 in
Outer diameter D21.26 in
Width B2.559 in
ISO bore code80
Radial section height (D−d)/270 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)49 of 63
Bore above smallest 61900-series size397 mm

Cross references & equivalents

Equivalent modelBrandMatch levelNote
61980-MA SKF full
Dimensions and internal design equivalent — standard interchange.
Same 400×540×65 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 61980 model number is decoded

61980 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 80 by five gives the 400 mm bore; the 540 mm outside diameter and 65 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 400 mm shaft under normal load, catalogue practice seats it on a m6 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. 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
  • edge loading from shaft deflection or housing misalignment
  • rolling-contact fatigue spalling after the rated L10 life is exceeded

Selection pitfalls — read before you substitute

  • Mount this 400 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 400 mm bore (70.0 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.
  • Storage matters for open bearings: 61980 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.
  • 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 61980 units.
  • Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 61900-series position can soften the mixture and leak — clean out the old fill before switching grease types.
  • Measure the shaft, do not trust the drawing: a 400 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 61980.
  • The open 61980 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 400 mm bore places 61980 in NTN's upper maximum-size range; at this diameter the bearing mass is substantial and mounting requires induction heating of the inner ring (max 120 °C) with a mechanical puller. NTN supplies a machined brass cage (suffix M) and expects oil lubrication with a defined relubrication interval.
  • NTN lists the grease limiting speed at only 990 r/min for 61980; this is a very 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.
  • NTN rates 61980 at 370 kN dynamic (C) and 535 kN static (C0), 16.4 kN fatigue load limit Cu; this is an upper heavy-load rating where the pressed-steel cage is not recommended — NTN supplies a machined brass cage (suffix M) and the static C0 must be verified against any shock or lifting loads the bearing sees during mounting.
  • At 41600 g (41.6 kg), 61980 is a very heavy bearing where handling and mounting method directly affect service life; NTN requires induction heating of the inner ring (max 120 °C), a mechanical puller for removal, and a defined lifting procedure to avoid damaging the machined brass cage.
  • The 400×540×65 mm envelope of 61980 gives a D/d ratio of 1.35 and only 70.0 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 370/535 kN load ratings, 16.4 kN fatigue load limit Cu NTN lists the grease limiting speed at 990 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 41600 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6980 on the 400×540×65 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61980 in a rated drive.
  • Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.
  • 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 61980 bearing?

A 61980 deep-groove ball bearing has a 400 mm bore, 540 mm outer diameter and 65 mm width (15.748 × 21.26 × 2.559 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 400 mm bore?

619 is a thin section one step above 618: 540×65 mm with a 70.0 mm radial section at 400 mm bore; a 6280 on the same bore is substantially larger and more heavily rated.

Are 61980 bearings from different brands interchangeable?

For boundary dimensions, yes: every brand's 61980 uses the same ISO 15 envelope (400×540×65 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 61980?

NTN lists the open 61980 under the bare designation 6980; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 400 mm bore envelope.

Does NTN offer 61980 with C3 clearance?

Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6980 is the correct choice.

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.