7320-NTN bearing: complete specifications & equivalents
The 7320-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 | 230 kN |
| Basic static load rating C0 | 193 kN |
| Fatigue load limit Pu | 12 kN |
| Limiting speed (mechanical) | 3500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 7180 g |
| Manufacturer designation | NTN 7320 |
| Standard | ISO 15 |
| Catalog version | NTN Ball and Roller Bearings CAT.No.2203E |
| Last verified | 2026-10-01 |
Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203E) · extracted 2026-10-01
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203E); 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 & 7300-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 7300-series | 10 mm |
| Largest outer diameter in 7300-series | 420 mm |
| Width range across 7300-series | 11–80 mm |
| Bore position in 7300-series (smallest first) | 21 of 32 |
| Bore above smallest 7300-series size | 90 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 7320 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×215×47 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 7320-BECBM | SKF | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
| 7320-BECBP | SKF | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
| 7320-BECBY | SKF | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
| 7320-BEM | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×215×47 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 7320-BEP | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×215×47 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application 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 7320-NTN model number is decoded
At 100 x 215 x 47 mm, NTN 7320 sits in the heavy-duty 7300 single-row family of the angular-contact programme. Decoding 7320: 73 is the single-row dimension series (heavy-duty 7300 single-row family), with 20 encodes the 100 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The radial section height here is 57.5 mm, and the catalogue couples that with C 230 kN / C0 193 kN. For a 100 mm shaft with combined load, the practical shortlist is this series, its 7200-series lighter section, and — where thrust reverses — a back-to-back pair rather than a single row. A 100 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted.
Typical equipment & failure modes
Common applications
- mining conveyor head-shaft positions
- marine auxiliary and winch gearbox shafts
- rolling-mill and metalworking drive shafts
- large pump, fan and compressor rotor shafts
Known failure patterns
- false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch
- loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow
- pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed
- flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share
- current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways
Selection pitfalls — read before you substitute
- Bearings of 100 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.
- The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.
- Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.
- Never use a four-point or double-row bearing as a like-for-like swap for a single 7320 without re-checking axial float, heat and housing width — the kinematics differ.
- A single-row angular contact left loose on the shaft to "help assembly" will fret the seat: the contact angle keeps driving the ring axially under load.
- The 230/193 kN ratings and 12 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7320; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive.
Frequently asked questions
What are the dimensions and catalogue ratings of NTN 7320?
7320 is a single-row angular contact ball bearing to ISO 15: 100 mm bore, 215 mm outside diameter, 47 mm width (3.937 x 8.465 x 1.85 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 230 kN, C0 193 kN and a 12 kN fatigue load limit Pu; the grease limiting speed is 3,500 r/min and the oil rating 4,700 r/min; mass about 7180 g.
How is the 7320 designation structured?
73 is the single-row dimension series (heavy-duty 7300 single-row family); 20 encodes the 100 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 215 mm OD and 47 mm width follow the ISO 15 boundary-dimension plan for that series.
Which axial direction does 7320 support?
One 7320 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact.
What lubrication speeds does NTN print for 7320?
Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,500 r/min and the oil rating 4,700 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit.
What should be checked before substituting another make for 7320?
The 100/215/47 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 230 kN / C0 193 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN Ball and Roller Bearings CAT.No.2203E on 2026-10-01. Read our editorial & correction policy.