7302B bearing: complete specifications & equivalents
The 7302B is a ISO 15 radial bearing sized 15 x 42 x 13 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 15 mm |
| Outer diameter D | 42 mm |
| Width B | 13 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 13.8 kN |
| Basic static load rating C0 | 6.65 kN |
| Fatigue load limit Pu | 0.52 kN |
| Limiting speed (mechanical) | 17000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 57 g |
| Manufacturer designation | NTN 7302B |
| 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 | 0.591 in |
|---|---|
| Outer diameter D | 1.654 in |
| Width B | 0.512 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 13.5 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) | 3 of 32 |
| Bore above smallest 7300-series size | 5 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 7302B | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier. |
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 7302B model number is decoded
7302B is an NTN single-row angular contact ball bearing: heavy-duty 7300 single-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 15 x 42 x 13 mm. The designation breaks down as 73 is the single-row dimension series (heavy-duty 7300 single-row family); 02 encodes the 15 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). On speed, the grease limiting speed is 17,000 r/min and the oil rating 22,000 r/min. Against a deep-groove bearing of the same 15 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated.
Typical equipment & failure modes
Common applications
- small gearbox pinion shafts with helical gears
- precision instrument and encoder support shafts
- small machine-tool spindle and live-centre positions
- high-speed router, grinder and woodworking spindles
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
- thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear
- machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface
- current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways
- lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated
Selection pitfalls — read before you substitute
- At 15 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.
- The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.
- Do not pair two random 7302B bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.
- Never use a four-point or double-row bearing as a like-for-like swap for a single 7302B without re-checking axial float, heat and housing width — the kinematics differ.
- The C0 of 6.65 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.
- The 13.8/6.65 kN ratings and 0.52 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7302B; 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 7302B?
7302B is a single-row angular contact ball bearing to ISO 15: 15 mm bore, 42 mm outside diameter, 13 mm width (0.591 x 1.654 x 0.512 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 13.8 kN, C0 6.65 kN and a 0.52 kN fatigue load limit Pu; the grease limiting speed is 17,000 r/min and the oil rating 22,000 r/min; mass about 57 g.
How is the 7302B designation structured?
73 is the single-row dimension series (heavy-duty 7300 single-row family); 02 encodes the 15 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 42 mm OD and 13 mm width follow the ISO 15 boundary-dimension plan for that series.
Which axial direction does 7302B support?
One 7302B alone takes thrust in one direction only, along its 40 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 7302B?
Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 17,000 r/min and the oil rating 22,000 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 7302B?
The 15/42/13 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 13.8 kN / C0 6.65 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.