61996 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 61996 model number is decoded

In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61996 carries bore code 96 = 480 mm. Outside diameter 650 mm and width 78 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 480 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

• Mount this 480 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 (85.0 mm section height at 480 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.
• The open 61996 has no lubricant retention: grease escapes and contaminants migrate straight into the 480×650×78 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
• Storage matters for open bearings: 61996 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.
• 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.
• Suffixes stack in a defined order — clearance follows the seal code, e.g. 61996-C3. No clearance suffix means normal CN clearance.
• The open 61996 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 480 mm bore places 61996 near the top of NTN's single-row deep-groove range; the pressed-steel cage is not viable at this diameter and NTN supplies a machined brass cage (suffix M). Housing stiffness and shaft alignment are critical, and the grease limiting speed is very low — specify oil lubrication and confirm the relubrication interval with NTN engineering.
• NTN lists the grease limiting speed at only 810 r/min for 61996; 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.
• At 480 kN dynamic load rating (C) and 770 kN static (C0), 21.5 kN fatigue load limit Cu, 61996 is a very-heavy-load bearing for large industrial gearboxes and steel-mill equipment; NTN supplies a machined brass cage (suffix M) and expects an application review, because catalogue L10 life alone does not capture the shock and misalignment loads at this rating.
• At 73000 g (73.0 kg), 61996 is an extremely heavy bearing at the top of the single-row deep-groove range; NTN mandates induction heating (max 120 °C), a dedicated lifting fixture, and a machined brass cage (suffix M). Consult NTN engineering for the mounting and handling procedure before installation.
• The 480×650×78 mm envelope of 61996 gives a D/d ratio of 1.35 and only 85.0 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 480/770 kN load ratings, 21.5 kN fatigue load limit Cu NTN lists the grease limiting speed at 810 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 73000 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6996 on the 480×650×78 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61996 in a rated drive.
• 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.
• 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.