61924-ZZ bearing: complete specifications & equivalents

Specification table

Source: catalog reference (NSK Rolling Bearings E1103 Part C) · extracted 2026-09-24

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 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. NSK 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

• Mount this 120 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 (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.
• Do not wash 61924-ZZ in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.
• Shielded 61924-ZZ units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.
• Never mix components between two 61924-ZZ units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.
• Vibration during standstill brinells the raceways of a 120 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.
• NSK catalogues the shielded version as 6924ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NSK order number when buying through an NSK channel.
• At 120 mm bore 61924 is in NSK's medium industrial range; the pressed-steel cage is standard, but large-section 63xx 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 NSK channel if the application sees impact loads.
• NSK rates 61924 at 58.5 kN dynamic (C) and 54 kN static (C0); 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 1210 g (1.2 kg), 61924 needs mechanical handling for mounting; NSK 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 in NSK's E1103 catalogue 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 58.5/54 kN load ratings, mass 1210 g here are NSK Rolling Bearings E1103 Part C catalogue 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. NSK does not tabulate reference or limiting speeds in the E1103 Part C dimension tables used for this page — consult NSK's separate speed-rating tables before high-speed service.
• NSK does not recommend washing new shielded or sealed bearings; the rust-preventive film on open units is compatible with standard lithium greases and needs no removal unless the application demands a special fill.
• When replacing a failed unit, inspect the shaft and housing seats before fitting the new 61924 — a new bearing pressed onto a worn or oval seat reproduces the original failure mode in a fraction of its expected life.