6328-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 6328-NSK model number is decoded

6328 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 28 by five gives the 140 mm bore; the 300 mm outside diameter and 62 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 140 mm shaft under normal load, catalogue practice seats it on a m6 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 140 mm bore the ring mass is significant: heat 6328 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 63xx medium series gains rating at 140 mm bore through a 300 mm OD and 62 mm width; the heavier rolling elements also trade away some speed versus a 6228.
• Storage matters for open bearings: 6328-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.
• Open bearings tolerate the highest speeds in the 6300-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6328 units.
• Deep-groove ball bearings tolerate only minutes of misalignment; if the 300 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6328-NSK.
• Shaft and housing fillets must clear the bearing chamfer so the 62 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.
• The open 6328 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 140 mm bore places 6328 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.
• NSK rates 6328 at 278 kN dynamic (C) and 246 kN static (C0); this is an extreme-load bearing at the top of the E1103 Part C single-row deep-groove range, where mounting, shaft stiffness and housing alignment dominate the achievable life. Consult NSK engineering for a full application review rather than relying on catalogue L10 alone.
• At 18500 g (18.5 kg), 6328 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 140×300×62 mm envelope of 6328 gives a D/d ratio of 2.14 and 80.0 mm radial section height — a heavy NSK section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.
• The 278/246 kN load ratings, mass 18500 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6328 on the 140×300×62 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6328 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.