6008-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 6008-NSK model number is decoded

6008 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 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. 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 a 40 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6008-NSK; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.
• Choosing the 60xx extra-light section saves radial space at 40 mm bore, but the trade-off is rating: if the drive sees shock or frequent start-stop cycles, re-check the L10 life against a 6208 before committing to the smaller envelope.
• The open 6008-NSK has no lubricant retention: grease escapes and contaminants migrate straight into the 40×68×15 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
• Storage matters for open bearings: 6008-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.
• 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-NSK drags the lip and overheats it.
• The housing bore for the 68 mm OD should be round within IT7; an oval bore pinches the outer ring of 6008-NSK and shows up later as two-point loaded raceway wear.
• The open 6008 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 40 mm bore puts 6008 in NSK's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty. NSK's VV non-contact seal is the high-speed choice here — DDU contact seal costs roughly 30–40% of the open-bearing speed ceiling.
• At 18.4 kN dynamic load rating (C) and 11.5 kN static (C0), 6008 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 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 NSK medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to NSK's listed speed ratings, and C3 clearance is the common choice for hot shafts.
• The 18.4/11.5 kN load ratings, mass 190 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6008 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. 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.
• NSK's VV non-contact seal keeps frictional torque close to the open 6008; in motor duty where heat build-up matters, VV is the usual compromise between debris protection and speed capability.