6330-NSK bearing: complete specifications & equivalents
The 6330-NSK is a ISO 15 radial bearing sized 150 x 320 x 65 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NSK |
| Bore diameter d | 150 mm |
| Outer diameter D | 320 mm |
| Width B | 65 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 300 kN |
| Basic static load rating C0 | 284 kN |
| Operating temperature | -40 to +150 °C |
| Mass | 22700 g |
| Manufacturer designation | NSK 6330 |
| Standard | ISO 15 |
| Catalog version | NSK Rolling Bearings E1103 Part C |
| Last verified | 2026-09-24 |
Source: catalog reference (NSK Rolling Bearings E1103 Part C) · extracted 2026-09-24
Dimensions in inches & 6300-series range
| Bore d | 5.906 in |
|---|---|
| Outer diameter D | 12.598 in |
| Width B | 2.559 in |
| ISO bore code | 30 |
| Radial section height (D−d)/2 | 85 mm |
| Smallest bore in 6300-series | 2 mm |
| Largest outer diameter in 6300-series | 500 mm |
| Width range across 6300-series | 3–95 mm |
| Bore position in 6300-series (smallest first) | 33 of 40 |
| Bore above smallest 6300-series size | 148 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6330-NTN | NTN | full Dimensions and internal design equivalent — standard interchange. | Same 150×320×65 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6330 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 150×320×65 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6330-M | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 150×320×65 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
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 6330-NSK model number is decoded
6330 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 30 by five gives the 150 mm bore; the 320 mm outside diameter and 65 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 150 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
Common applications
- pulp and paper machinery
- medium and heavy industrial drives
- large gearboxes
- industrial fans and blowers
Known failure patterns
- contamination wear from dust and dirt ingress through the open arrangement
- lubricant starvation when no regreasing interval is maintained
- brinelling from static overload or hammering during mounting
- false brinelling from vibration while the shaft is stationary
Selection pitfalls — read before you substitute
- Mount this 150 mm bore bearing by heating the inner ring (induction heater, max 120 °C) — never drive it home through the outer ring or balls, that brinells the raceways.
- The 63xx medium section at 150 mm bore gains dynamic rating through larger rolling elements on a 320 mm OD; the penalty is mass and a lower limiting speed than the 6230 — do not specify it for speed-critical shafts.
- The open 6330-NSK has no lubricant retention: grease escapes and contaminants migrate straight into the 150×320×65 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
- Storage matters for open bearings: 6330-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.
- A 150 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.
- Do not quieten a noisy bearing by preloading it: the 6300-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.
- The open 6330 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 150 mm bore places 6330 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 6330 at 300 kN dynamic (C) and 284 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 22700 g (22.7 kg), 6330 is a very heavy NSK bearing where handling and mounting method directly affect service life; NSK requires induction heating of the inner ring (max 120 °C), a mechanical puller for removal, and a defined lifting procedure to avoid damaging the cage.
- The 150×320×65 mm envelope of 6330 gives a D/d ratio of 2.13 and 85.0 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 300/284 kN load ratings, mass 22700 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6330 on the 150×320×65 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6330 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's VV non-contact seal keeps frictional torque close to the open 6330; in motor duty where heat build-up matters, VV is the usual compromise between debris protection and speed capability.
- 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.
Frequently asked questions
What are the dimensions of a 6330-NSK bearing?
A 6330-NSK deep-groove ball bearing has a 150 mm bore, 320 mm outer diameter and 65 mm width (5.906 × 12.598 × 2.559 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields.
What lubrication does 6330-NSK need?
The open 6330-NSK is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval.
How does the 6330 bore code work?
The last two digits of 6330 are bore code 30, giving 30 × 5 = 150 mm bore. The 320 mm outside diameter and 65 mm width follow the ISO 15 diameter series, not the bore code alone.
What is the NSK order number for an open 6330?
NSK lists the open 6330 under the bare designation 6330; protected versions use suffixes ZZ (steel shields), VV (non-contact rubber seals) and DDU (contact rubber seals) on the same 150 mm bore envelope.
Does NSK offer 6330 with C3 clearance?
NSK lists C3 (and C4) internal-clearance options for most deep-groove sizes under the same base designation; the clearance is fixed at manufacture, so specify it at order time rather than planning to adjust later.
Reviewed & verified by the MPN Base engineering desk against source catalog NSK Rolling Bearings E1103 Part C on 2026-09-24. Read our editorial & correction policy.