1304 Bearing — Cross-Reference & Equivalents
The 1304 is a self-aligning ball bearing with ISO 15 boundary dimensions 20×52×15 mm. The table below lists how 8 major brands designate it, with catalog links and interchange notes.
Replacing a 1304? The cross-reference table below gives the equivalent part number for every major brand — but read the interchange rules first: an identical size is not always a safe swap.
Specifications
| Bore (d) | 20 mm |
|---|---|
| Outer Diameter (D) | 52 mm |
| Width (B) | 15 mm |
| Type | Self-Aligning Ball Bearing |
| Standard | ISO 15 |
Cross-Reference by Brand
| Brand | Part No. | Boundary dims | Catalog |
|---|---|---|---|
| SKF | 1304 | match | SKF catalog ↗ |
| NSK | 1304 | match | NSK catalog ↗ |
| FAG | 1304 | match | FAG catalog ↗ |
| NTN | 1304 | match | NTN catalog ↗ |
| KOYO | 1304 | match | KOYO catalog ↗ |
| NACHI | 1304 | match | NACHI catalog ↗ |
| Timken | 1304 | match | Timken catalog ↗ |
| INA | 1304 | match | INA catalog ↗ |
Interchange notes
All brands build this designation to the same ISO 15 boundary dimensions (d, D, B), so the mounting envelope is interchangeable. For self-aligning ball bearings, matching dimensions is NOT enough: (1) Two ball rows run on a single spherical raceway in the outer ring, letting the bearing swivel to absorb shaft misalignment — replacing it with a same-size deep groove ball bearing removes this and turns misalignment into edge loading. (2) A 'K' suffix means a tapered bore (taper 1:12) for an adapter/withdrawal sleeve; clearance is set during mounting by drive-up, not by shaft fit, so the tapered- and cylindrical-bore versions are NOT interchangeable. (3) The wide 22/23 series is not equivalent to the normal 12/13 series — it changes permissible misalignment angle. (4) Match internal clearance (CN/C2/C3), which alters the self-aligning angle, plus seal (-2RS) and cage type. Load ratings (dynamic Cr, static C0r) are intentionally NOT listed here: they vary by brand and internal design and are a safety-critical selection parameter — read them directly from the manufacturer catalog linked in the table above.
Where to buy a 1304
Compare current listings and prices for the 1304 across brands and sellers:
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FAQ
What bearings are equivalent to a 1304?
The 1304 is built to ISO 15 boundary dimensions 20×52×15 mm by SKF, NSK, FAG, NTN, KOYO, NACHI, Timken, INA. All share the same mounting envelope; match clearance, precision class and (where applicable) seal suffix before substituting.
What are the dimensions of a 1304 bearing?
Bore 20 mm, outer diameter 52 mm, B 15 mm (ISO 15).
Is the 1304 interchangeable with a same-size deep groove bearing?
No. The 1304 shares its 20×52×15 mm envelope, but its two ball rows sit on a spherical outer raceway so it can swivel and absorb shaft misalignment — a rigid deep groove bearing of the same size cannot. Also check the bore: a 'K' suffix is a 1:12 tapered bore for a sleeve and is not interchangeable with the straight-bore version. Match internal clearance (CN/C2/C3) and seal type.
Related sizes
Boundary-dimension cross-reference only. Per the applicable ISO standard (ISO 15 for ball, ISO 355 for tapered), the boundary dimensions are common across brands, so the mounting envelope is interchangeable. This is NOT a drop-in part equivalence. Internal clearance, precision class, seal/shield type (where applicable), cage material and factory lubrication are encoded in brand-specific suffixes and must be matched separately. Always verify against the manufacturer's catalog before substituting.