2307 bearing: complete specifications & equivalents

The 2307 is a ISO 15 radial bearing sized 35 x 80 x 31 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.

Bearing dimension schematic Front view shows outer diameter D and bore d; side section shows width B. D = 80 mm d = 35 B = 31 mm side section front view
Principal dimensions: bore d 35 mm, outer diameter D 80 mm, width B 31 mm. Schematic, not to scale.

Specification table

ParameterValue
Brand NTN
Bore diameter d 35 mm
Outer diameter D 80 mm
Width B 31 mm
Seal / shield open
Basic dynamic load rating C 40 kN
Basic static load rating C0 11.3 kN
Fatigue load limit Pu 0.48 kN
Limiting speed (mechanical) 7100 rpm
Mass 671 g
Manufacturer designation 2307S
Standard ISO 15
Catalog version CAT. No. 2203-3/E 2024
Last verified 2026-09-25

Source: catalog reference (CAT. No. 2203-3/E 2024) · extracted 2026-09-25

Parameters extracted from the official NTN Ball and Roller Bearings catalogue (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 & 2300-series range

Bore d 1.378 in
Outer diameter D 3.15 in
Width B 1.22 in
ISO bore code 07
Radial section height (D−d)/2 22.5 mm
Smallest bore in 2300-series 10 mm
Largest outer diameter in 2300-series 215 mm
Width range across 2300-series 17–73 mm
Bore position in 2300-series (smallest first) 8 of 21
Bore above smallest 2300-series size 25 mm

Cross references & equivalents

No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.

How the 2307 model number is decoded

In the 2300-series (ISO 15 dimension series) the leading digits 23 mark a double-row self-aligning ball bearing and the last two digits encode the bore: 2307 carries bore code 07 = 35 mm. Outside diameter 80 mm and width 31 mm follow the ISO 15 general plan. The cylindrical bore fits directly on a machined shaft seat; a tapered-bore K variant is available for adapter-sleeve mounting. Two rows of balls run on a common sphered outer raceway, allowing the inner ring to pivot and compensate for shaft deflection or housing misalignment.

Typical equipment & failure modes

Common applications

  • centrifugal pump shafts
  • small gearbox input/output shafts
  • conveyor roller and pulley shafts
  • agricultural equipment (harvesters, balers)

Known failure patterns

  • contamination wear from dust and dirt ingress through the open arrangement
  • lubricant starvation when no regreasing interval is maintained
  • raceway smearing under marginal lubrication at start-up
  • fretting corrosion on a loose shaft seat

Selection pitfalls — read before you substitute

  • At a 35 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 2307; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.
  • The 23xx heavy wide-section at 35 mm bore is built for high-load, lower-speed duty; specifying it in a high-rpm application gives excess heat and short grease life — use 12/13 there.
  • The open 2307 has no lubricant retention: grease escapes and contaminants migrate straight into the 35×80×31 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
  • Open bearings tolerate the highest speeds in the 2300-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 2307 units.
  • Suffixes stack in a defined order — clearance follows the bore code, e.g. 2307-C3. No clearance suffix means normal CN clearance.

Frequently asked questions

What are the dimensions of a 2307 self-aligning ball bearing?

A 2307 self-aligning ball bearing has a 35 mm bore, 80 mm outer diameter and 31 mm width, per ISO 15 boundary dimensions. This is the cylindrical-bore version; a tapered-bore K variant is available for adapter-sleeve mounting.

How does the 2307 bore code work?

The last two digits of 2307 are bore code 07, giving 07 × 5 = 35 mm bore. The 80 mm outside diameter and 31 mm width follow the ISO 15 diameter series, not the bore code alone.

What does the open suffix mean on 2307?

A bare 2307 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication.

How does the 2300 compare with other self-aligning series at the same 35 mm bore?

The 23xx is the wide heavy section: 80×31 mm, 22.5 mm radial section at 35 mm bore — the highest-capacity double-row self-aligning option here, aimed at lower-speed, high-load shafts.

Reviewed & verified by the MPN Base engineering desk against source catalog CAT. No. 2203-3/E 2024 on 2026-09-25. Read our editorial & correction policy.