6320-NTN bearing: complete specifications & equivalents
The 6320-NTN is a ISO 15 radial bearing sized 100 x 215 x 47 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 100 mm |
| Outer diameter D | 215 mm |
| Width B | 47 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 192 kN |
| Basic static load rating C0 | 141 kN |
| Fatigue load limit Pu | 8.75 kN |
| Limiting speed (mechanical) | 3200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 7000 g |
| Manufacturer designation | 6320 |
| Standard | ISO 15 |
| Catalog version | NTN Ball and Roller Bearings CAT.No.2203-3/E (2024) |
| Last verified | 2026-09-25 |
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.
Dimensions in inches & 6300-series range
| Bore d | 3.937 in |
|---|---|
| Outer diameter D | 8.465 in |
| Width B | 1.85 in |
| ISO bore code | 20 |
| Radial section height (D−d)/2 | 57.5 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) | 27 of 40 |
| Bore above smallest 6300-series size | 98 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6320-2RS-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×215×47 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6320-RSR | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×215×47 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6320-ZZ-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×215×47 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6320 | NSK | full Dimensions and internal design equivalent — standard interchange. | Same 100×215×47 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6320-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×215×47 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6320-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×215×47 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6320-M | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×215×47 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 6320-NTN model number is decoded
In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6320 carries bore code 20 = 100 mm. Outside diameter 215 mm and width 47 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 100 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).
Typical equipment & failure modes
Common applications
- medium and heavy industrial drives
- large gearboxes
- industrial fans and blowers
- hoists and winches
Known failure patterns
- contamination wear from dust and dirt ingress through the open arrangement
- lubricant starvation when no regreasing interval is maintained
- rolling-contact fatigue spalling after the rated L10 life is exceeded
- brinelling from static overload or hammering during mounting
Selection pitfalls — read before you substitute
- Mount this 100 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 series gains rating at 100 mm bore through a 215 mm OD and 47 mm width; the heavier rolling elements also trade away some speed versus a 6220.
- The open 6320-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 100×215×47 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
- 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 6320 units.
- Never mix components between two 6320-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.
- A 100 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.
- The open 6320 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.
- At 100 mm bore 6320 is in NTN's medium industrial range; the pressed-steel cage is standard but large-section 63xx/64xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.
- NTN lists the grease limiting speed at 3200 r/min for 6320; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.
- At 192 kN dynamic load rating (C) and 141 kN static (C0), 8.75 kN fatigue load limit Cu, 6320 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.
- At 7000 g (7.0 kg), 6320 is a heavy 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 100×215×47 mm envelope of 6320 gives a D/d ratio of 2.15 and 57.5 mm radial section height — a heavy 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 192/141 kN load ratings, 8.75 kN fatigue load limit Cu NTN lists the grease limiting speed at 3200 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 7000 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6320 on the 100×215×47 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6320 in a rated drive.
- NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.
- NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6320 is listed.
Frequently asked questions
What are the dimensions of a 6320-NTN bearing?
A 6320-NTN deep-groove ball bearing has a 100 mm bore, 215 mm outer diameter and 47 mm width (3.937 × 8.465 × 1.85 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields.
How does the 6300 compare with other series at the same 100 mm bore?
The '3' is the medium diameter series: 215×47 mm, 57.5 mm radial section at 100 mm bore, carrying more load than a 6220 but needing a larger housing bore and giving up some speed.
Are 6320 bearings from different brands interchangeable?
For boundary dimensions, yes: every brand's 6320 uses the same ISO 15 envelope (100×215×47 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting.
What is the NTN order number for an open 6320?
NTN lists the open 6320 under the bare designation 6320; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 100 mm bore envelope.
What cage does NTN fit in 6320?
Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN Ball and Roller Bearings CAT.No.2203-3/E (2024) on 2026-09-25. Read our editorial & correction policy.