6008-RSR-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 6008-RSR-NTN model number is decoded

6008-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 08 by five gives the 40 mm bore; the 68 mm outside diameter and 15 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 40 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. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6008LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• At a 40 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6008-RSR-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.
• The 60xx extra-light section at 40 mm bore uses a smaller 68 mm OD than a 6208; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.
• RSR low-friction seals on 6008-RSR-NTN run faster than contact-seal 6008-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6008-2RS instead.
• The low-drag lip of 6008-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.
• Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 15 mm-wide ring of 6008-RSR-NTN drags the lip and overheats it.
• Never mix components between two 6008-RSR-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.
• NTN catalogues this low-friction non-contact seal as 6008LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).
• The 40 mm bore puts 6008 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.
• At 7300 r/min the grease limiting speed for 6008 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.
• At 18.6 kN dynamic load rating (C) and 11.5 kN static (C0), 0.89 kN fatigue load limit Cu, 6008 is a medium-load 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 NTN catalogue.
• At 190 g, 6008 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.
• The 40×68×15 mm envelope of 6008 gives a D/d ratio of 1.70 and 14.0 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.
• The 18.6/11.5 kN load ratings, 0.89 kN fatigue load limit Cu NTN lists the grease limiting speed at 7300 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 190 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6008LLB on the 40×68×15 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6008 in a rated drive.
• 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.
• Standard catalogue stock of 6008 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.