61984 bearing: complete specifications & equivalents

Specification table

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.

Cross references & equivalents

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 61984 model number is decoded

In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61984 carries bore code 84 = 420 mm. Outside diameter 560 mm and width 65 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 420 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

Selection pitfalls — read before you substitute

• At 420 mm bore the ring mass is significant: heat 61984 on an induction heater (max 120 °C), never over an open flame, and plan puller access or a withdrawal sleeve now for the day it has to come off again.
• The 619xx thin section (70.0 mm section height at 420 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.
• Storage matters for open bearings: 61984 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 61984 units.
• Never mix components between two 61984 units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.
• Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 65 mm-wide ring of 61984 drags the lip and overheats it.
• The open 61984 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 420 mm bore places 61984 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 940 r/min for 61984; 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 61984 at 380 kN dynamic (C) and 560 kN static (C0), 16.8 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 43400 g (43.4 kg), 61984 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 420×560×65 mm envelope of 61984 gives a D/d ratio of 1.33 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 380/560 kN load ratings, 16.8 kN fatigue load limit Cu NTN lists the grease limiting speed at 940 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 43400 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6984 on the 420×560×65 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61984 in a rated drive.
• Order the C3 internal-clearance version (61984 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.
• 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.