2304-E-2RS1TN9 bearing: complete specifications & equivalents

The 2304-E-2RS1TN9 is a ISO 15 radial bearing sized 20 x 52 x 21 mm (bore x OD x width) with 2RS sealing. 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 = 52 mm d = 20 B = 21 mm side section front view
Principal dimensions: bore d 20 mm, outer diameter D 52 mm, width B 21 mm. Schematic, not to scale.

Specification table

ParameterValue
Brand SKF
Bore diameter d 20 mm
Outer diameter D 52 mm
Width B 21 mm
Material GCr15
Seal / shield 2RS
Internal clearance CN
Tolerance class P0
Cage polymer (PA66 glass-fibre reinforced)
Basic dynamic load rating C 14.3 kN
Basic static load rating C0 4 kN
Fatigue load limit Pu 0.21 kN
Limiting speed (mechanical) 9000 rpm
Operating temperature -40 to +120 °C
Mass 210 g
Manufacturer designation 2304 E-2RS1TN9
Standard ISO 15
Catalog version SKF PUB BU/P1 17000/1 EN (Oct 2018)
Last verified 2026-09-27

Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-27

Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018)); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.

Dimensions in inches & 2300-series range

Bore d 0.787 in
Outer diameter D 2.047 in
Width B 0.827 in
ISO bore code 04
Radial section height (D−d)/2 16 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) 5 of 21
Bore above smallest 2300-series size 10 mm

Cross references & equivalents

Equivalent modelBrandMatch levelNote
2304 NTN partial
Main dimensions match; tolerances, seals or internal clearance differ.
NTN bearing 2304S on the same 20×52×21 mm envelope, but catalogue C/C0 differ (14.3/4 kN vs 18.5/4.7 kN) — envelope interchange only after a load check.
2304K NTN partial
Main dimensions match; tolerances, seals or internal clearance differ.
NTN bearing 2304SK on the same 20×52×21 mm envelope, but catalogue C/C0 differ (14.3/4 kN vs 18.5/4.7 kN) — envelope interchange only after a load check.
2304-TN9 SKF partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 20×52×21 mm envelope, but catalogue C/C0 differ between executions (14.3/4 kN vs 18.2/4.75 kN) — boundary dimensions match, not a load-rating equivalent.

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 2304-E-2RS1TN9 model number is decoded

The 23xx series is the wide medium-section self-aligning ball bearing (ISO dimension series 23). the last two digits encode the bore: 2304 carries code 04 = 20 mm (code × 5). Envelope 20×52×21 mm (0.787×2.047×0.827 in) with a 16.0 mm radial section height, C 14.3 kN, C0 4 kN and Pu 0.21 kN. SKF spells the sealed execution 2304 E-2RS1TN9 (suffix 2RS1): two contact elastomer lips over a lifetime grease fill; the lips add drag, and no thermal reference speed is published. The E-2RS1TN9 suffix identifies the glass-fibre-reinforced polyamide 66 cage execution. The bore is cylindrical (straight), for a press-fit on a 20 mm shaft. Limiting speed 9000 r/min, catalogue mass 210 g.

Typical equipment & failure modes

Common applications

  • food-processing conveyors
  • small electric motors
  • conveyor idler rollers
  • agricultural machinery shafts

Known failure patterns

  • fine dust or moisture passing a worn seal lip in dirty or wet duty
  • grease loss when the sealed-for-life cavity is overheated with no relubrication path
  • raceway smearing under marginal lubrication at start-up
  • electrical pitting in VFD-driven motors without shaft grounding

Selection pitfalls — read before you substitute

  • Catalogue ratings for 2304-E-2RS1TN9 (C 14.3 kN, C0 4 kN) are SKF figures from PUB BU/P1 17000; geometry revisions can change ratings without changing the designation, so keep the catalogue edition with the specification.
  • Catalogue ratings for 2304-E-2RS1TN9 (C 14.3 kN, C0 4 kN) are SKF figures from PUB BU/P1 17000; geometry revisions can change ratings without changing the designation, so keep the catalogue edition with the specification.
  • Do not wash 2304-E-2RS1TN9 with solvent — the lifetime grease fill is sealed in, and solvent destroys the grease without a way to repack it.
  • The E-2RS1TN9 suffix on 2304-E-2RS1TN9 denotes a glass-fibre-reinforced polyamide 66 cage: quiet and light at the 9000 r/min limiting speed, but it softens above roughly 120 °C — check the oil temperature in hot drives.
  • Catalogue ratings for 2304-E-2RS1TN9 (C 14.3 kN, C0 4 kN) are SKF figures from PUB BU/P1 17000; geometry revisions can change ratings without changing the designation, so keep the catalogue edition with the specification.
  • Mount 2304-E-2RS1TN9 by heating the inner ring (max 120 °C) on a cylindrical bore — driving it home through the outer ring or balls brinells the raceways.

Frequently asked questions

What are the dimensions of 2304-E-2RS1TN9?

SKF 2304 E-2RS1TN9 measures 20 mm bore × 52 mm OD × 21 mm width (0.787 × 2.047 × 0.827 in), mass about 210 g. It has two contact rubber seals (2RS1) and a lifetime grease fill.

How does the bore code in 2304 work?

The final two digits of 2304 are bore code 04, multiplied by 5 to give 20 mm.

What is the speed rating of 2304-E-2RS1TN9?

SKF publishes only the 9000 r/min limiting speed for this execution; sealed variants have no thermal reference speed because seal and grease life govern.

How much misalignment can 2304-E-2RS1TN9 tolerate?

Self-aligning ball bearings tolerate roughly 2–3° of static misalignment for open executions; sealed 2RS1 variants like 2304-E-2RS1TN9 allow less (about 1°) because the seal lip binds first.

Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-27. Read our editorial & correction policy.