61920-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 61920-ZZ model number is decoded

In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61920 carries bore code 20 = 100 mm. Outside diameter 140 mm and width 20 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 100 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NSK catalogue order number: 6920ZZ (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 100 mm of 61920-ZZ 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 (20.0 mm section height at 100 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.
• Do not wash 61920-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 61920-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.
• Do not quieten a noisy bearing by preloading it: the 61900-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.
• The housing bore for the 140 mm OD should be round within IT7; an oval bore pinches the outer ring of 61920-ZZ and shows up later as two-point loaded raceway wear.
• NSK catalogues the shielded version as 6920ZZ — 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 100 mm bore 61920 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 61920 at 47 kN dynamic (C) and 42 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 828 g, 61920 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.
• The 100×140×20 mm envelope of 61920 gives a D/d ratio of 1.40 and 20.0 mm radial section height — this NSK thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.
• The 47/42 kN load ratings, mass 828 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6920ZZ on the 100×140×20 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61920 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's VV non-contact seal keeps frictional torque close to the open 61920; in motor duty where heat build-up matters, VV is the usual compromise between debris protection and speed capability.
• When replacing a failed unit, inspect the shaft and housing seats before fitting the new 61920 — a new bearing pressed onto a worn or oval seat reproduces the original failure mode in a fraction of its expected life.