61924-ZZ-NTN 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 61924-ZZ-NTN model number is decoded

61924-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 24 by five gives the 120 mm bore; the 165 mm outside diameter and 22 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 120 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. NTN catalogue order number: 6924ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Large bores like the 120 mm of 61924-ZZ-NTN demand clean, burr-free seats; one raised burr under a ring this size cocks the bearing and concentrates load at the raceway edge, cutting life drastically.
• The 619xx thin section (22.5 mm section height at 120 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.
• ZZ shields are non-contact: 61924-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61924-2RS for that.
• Shielded 61924-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.
• Suffixes stack in a defined order — clearance follows the seal code, e.g. 61924-ZZ-NTN-C3. No clearance suffix means normal CN clearance.
• The housing bore for the 165 mm OD should be round within IT7; an oval bore pinches the outer ring of 61924-ZZ-NTN and shows up later as two-point loaded raceway wear.
• NTN catalogues the shielded version as 6924ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.
• At 120 mm bore 61924 is in NTN's medium industrial range; the pressed-steel cage is standard but large-section 63xx/64xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.
• NTN lists the grease limiting speed at 3800 r/min for 61924; 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.
• NTN rates 61924 at 59 kN dynamic (C) and 54 kN static (C0), 3.05 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.
• At 1150 g (1.1 kg), 61924 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 120×165×22 mm envelope of 61924 gives a D/d ratio of 1.38 and only 22.5 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 59/54 kN load ratings, 3.05 kN fatigue load limit Cu NTN lists the grease limiting speed at 3800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 1150 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6924ZZ on the 120×165×22 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61924 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.
• 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.