61930 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 61930 model number is decoded

In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61930 carries bore code 30 = 150 mm. Outside diameter 210 mm and width 28 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 150 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 NSK catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (steel shields), VV (non-contact rubber seals) and DDU (contact rubber seals).

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• At 150 mm bore the ring mass is significant: heat 61930 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 at 150 mm bore (30.0 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.
• The open 61930 has no lubricant retention: grease escapes and contaminants migrate straight into the 150×210×28 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
• Storage matters for open bearings: 61930 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.
• 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.
• Suffixes stack in a defined order — clearance follows the seal code, e.g. 61930-C3. No clearance suffix means normal CN clearance.
• The open 61930 has no integral sealing; in the NSK E1103 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), VV (non-contact rubber seals) and DDU (contact rubber seals). NSK does not offer a low-torque contact seal equivalent to NTN's LLH in this catalogue — for high-speed sealed duty specify the VV non-contact seal and an external housing labyrinth.
• The 150 mm bore places 61930 at the lower end of NSK's large-size range; at these diameters the pressed-steel cage is speed-limited and NSK commonly supplies a machined brass cage (suffix M) as an option. Verify cage material and relubrication interval with the NSK distributor, and do not extrapolate small-bore speed ratings to this size.
• At 93.5 kN dynamic load rating (C) and 90.5 kN static (C0), 61930 is a heavy-load NSK bearing for industrial gearboxes and large conveyors; NSK expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.
• At 3010 g (3.0 kg), 61930 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 150×210×28 mm envelope of 61930 gives a D/d ratio of 1.40 and 30.0 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 93.5/90.5 kN load ratings, mass 3010 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6930 on the 150×210×28 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61930 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.
• Keep NSK bearings in the original packaging until fitting: the wrapper carries the production lot, and the unopened shelf life of greased sealed units is typically quoted at three to five years in dry, vibration-free storage.
• Standard P0 runout from NSK is adequate up to the catalogue limiting speed on ground shaft seats; spindle or instrument positions should specify P6/P5 accuracy explicitly — it is a different order code, not a sorting of standard stock.