6040 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 6040 model number is decoded

In the 6000-series (diameter series 0 of ISO 15) the last two digits encode the bore: 6040 carries bore code 40 = 200 mm. Outside diameter 310 mm and width 51 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 200 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 200 mm bore the ring mass is significant: heat 6040 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.
• Choosing the 60xx extra-light section saves radial space at 200 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 6240 before committing to the smaller envelope.
• Storage matters for open bearings: 6040 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.
• Open bearings tolerate the highest speeds in the 6000-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6040 units.
• A 200 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.
• 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.
• The open 6040 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 200 mm bore places 6040 in 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.
• NSK rates 6040 at 228 kN dynamic (C) and 226 kN static (C0); this heavy-load rating is at the upper end of the E1103 Part C single-row deep-groove extract — NSK supplies a machined brass cage (suffix M) and expects an application review, because catalogue L10 life alone does not capture shock and misalignment loads at this rating.
• At 12000 g (12.0 kg), 6040 is a heavy NSK bearing that requires a crane or hoist for handling; induction-heat the inner ring (max 120 °C) and use a mechanical puller for removal — never apply heat directly to the balls or cage.
• The 200×310×51 mm envelope of 6040 gives a D/d ratio of 1.55 and 55.0 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 228/226 kN load ratings, mass 12000 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6040 on the 200×310×51 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6040 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.
• 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.
• NSK's VV non-contact seal keeps frictional torque close to the open 6040; in motor duty where heat build-up matters, VV is the usual compromise between debris protection and speed capability.