6011-NSK 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 6011-NSK model number is decoded

6011 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 11 by five gives the 55 mm bore; the 90 mm outside diameter and 18 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 55 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. 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

• Interference on a 55 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6011 with C3 clearance and re-check the residual value after mounting.
• The 60xx extra-light section at 55 mm bore uses a smaller 90 mm OD than a 6211; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.
• The open 6011-NSK has no lubricant retention: grease escapes and contaminants migrate straight into the 55×90×18 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
• Storage matters for open bearings: 6011-NSK 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.
• Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.
• Do not quieten a noisy bearing by preloading it: the 6000-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.
• The open 6011 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.
• At 55 mm bore 6011 is in NSK's upper general-purpose range; the pressed-steel cage is standard, but mid-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.
• At 31 kN dynamic load rating (C) and 21.2 kN static (C0), 6011 is a medium-load NSK bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NSK catalogue.
• At 381 g, 6011 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 55×90×18 mm envelope of 6011 gives a D/d ratio of 1.64 and 17.5 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 31/21.2 kN load ratings, mass 381 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6011 on the 55×90×18 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6011 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.
• When replacing a failed unit, inspect the shaft and housing seats before fitting the new 6011 — a new bearing pressed onto a worn or oval seat reproduces the original failure mode in a fraction of its expected life.
• 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.