MPNbase

20×52×15 mm bearings

43 models from 4 brands across 4 types share this ISO 15 envelope: 20 mm bore, 52 mm outside diameter, 15 mm width (0.787×2.047×0.591 in), 16 mm radial section.

43 models fit this space 4 brands 43 with catalogue C rating

Dimensional interchange — verify before substituting

These bearings are interchangeable on boundary dimensions per ISO 15 — same bore, OD and width. They are not guaranteed drop-in equivalents: compare load ratings, seals, clearance, cage, precision and axial-locating design for the specific duty. Models without a catalogue C rating on this site carry ISO 15 geometry only; request the manufacturer table before a load-critical replacement.

Model Type Brand Seal Clearance C (kN) C0 (kN) Mass (g)
1304 Self-Aligning Ball NTN open — 12.6 3.35 164
1304-ETN9 Self-Aligning Ball SKF open CN 14.3 4 160
1304K Self-Aligning Ball NTN open — 12.6 3.35 164
6304 Deep Groove Ball SKF open CN 16.8 7.8 140
6304-2RS Deep Groove Ball SKF 2RS CN 16.8 7.8 150
6304-2RS-FAG Deep Groove Ball FAG 2RS CN 16.9 7.9 155
6304-2RS-NSK Deep Groove Ball NSK 2RS CN 17.5 7.9 145
6304-2RS-NTN Deep Groove Ball NTN 2RS CN 17.6 7.9 144
6304-FAG Deep Groove Ball FAG open CN 16.9 7.9 144
6304-NSK Deep Groove Ball NSK open CN 17.5 7.9 145
6304-NTN Deep Groove Ball NTN open CN 17.6 7.9 144
6304-RSR Deep Groove Ball SKF RSR CN 15.9 7.8 150
6304-RSR-NSK Deep Groove Ball NSK RSR CN 17.5 7.9 145
6304-RSR-NTN Deep Groove Ball NTN RSR CN 17.6 7.9 144
6304-ZZ Deep Groove Ball SKF ZZ CN 16.8 7.8 150
6304-ZZ-FAG Deep Groove Ball FAG ZZ CN 16.9 7.9 146
6304-ZZ-NSK Deep Groove Ball NSK ZZ CN 17.5 7.9 145
6304-ZZ-NTN Deep Groove Ball NTN ZZ CN 17.6 7.9 144
7304 Angular Contact Ball SKF open CN 17.4 9.5 140
7304-ACCBM Angular Contact Ball SKF open CN 20.8 11.2 140
7304-BE-2RZP Angular Contact Ball SKF RSR CN 17.4 9.5 140
7304-BECBM Angular Contact Ball SKF open CN 19 10 140
7304-BECBP Angular Contact Ball SKF open CN 19 10 140
7304-BECBPH Angular Contact Ball SKF open CN 19 10 140
7304-BECBY Angular Contact Ball SKF open CN 20.4 11.2 140
7304-BEP Angular Contact Ball SKF open CN 17.4 9.5 140
7304-NTN Angular Contact Ball NTN open CN 20.7 10.4 138
7304B Angular Contact Ball NTN open CN 19.2 9.65 141
N304-ECP Cylindrical Roller SKF open CN 35.5 26 150
N304EA Cylindrical Roller NTN open CN 37.5 26.9 147
NF304EA Cylindrical Roller NTN open CN 37.5 26.9 147
NJ304-ECP Cylindrical Roller SKF open CN 35.5 26 150
NJ304EA Cylindrical Roller NTN open CN 37.5 26.9 147
NU304 Cylindrical Roller SKF open CN 35.5 26 140
NU304EA Cylindrical Roller NTN open CN 37.5 26.9 147
NUP304-ECP Cylindrical Roller SKF open CN 35.5 26 160
NUP304EA Cylindrical Roller NTN open CN 37.5 26.9 147
QJ-304-MA Angular Contact Ball SKF open CN 32 21.6 180
QJ-304-N2MA Angular Contact Ball SKF open CN 32 21.6 180
QJ-304-N2PHAS Angular Contact Ball SKF open CN 32 21.6 180
W6304 Deep Groove Ball SKF open CN 13.8 7.8 136
W6304-2RS Deep Groove Ball SKF 2RS CN 13.8 7.8 143
W6304-ZZ Deep Groove Ball SKF ZZ CN 13.8 7.8 144

Note: catalogue dynamic load ratings for this envelope span 12.6– 37.5 kN — a 198% spread between designs in the very same 20×52×15 mm space. The higher-rated unit is not an upgrade for every duty (it may run at lower limiting speed), but ignoring the gap will over- or under-life the replacement.

Substitution verification checklist

  1. Load rating. Check C (dynamic) and C0 (static) against the original life calculation — the table above shows which models carry verified catalogue values.
  2. Sealing. Open, -ZZ shields and -2RS contact seals are not equivalent in friction, speed or contamination protection; match the housing environment, not just the suffix on the old box.
  3. Internal clearance. CN/C3/C4 changes with fit and operating temperature; an interference inner-ring mount commonly needs C3 where the bench bearing ran CN.
  4. Cage and precision. Stamped steel, machined brass and polymer cages, and P0/P6/P5 tolerance classes, carry different speed and shock limits.
  5. Locating behaviour. Within one envelope an NU cylindrical roller floats axially while an NJ/NUP locates; ball designs take thrust that roller locating schemes do not. Preserve the shaft's locating arrangement.

Browse all 20 mm bore bearings for wider or narrower sections, or open a model page for naming-rule decode, applications and graded cross references: 1304, 1304-ETN9, 1304K, 6304, 6304-2RS, 6304-2RS-FAG, 6304-2RS-NSK, 6304-2RS-NTN, 6304-FAG, 6304-NSK, 6304-NTN, 6304-RSR, 6304-RSR-NSK, 6304-RSR-NTN, 6304-ZZ, 6304-ZZ-FAG, 6304-ZZ-NSK, 6304-ZZ-NTN, 7304, 7304-ACCBM, 7304-BE-2RZP, 7304-BECBM, 7304-BECBP, 7304-BECBPH, 7304-BECBY, 7304-BEP, 7304-NTN, 7304B, N304-ECP, N304EA, NF304EA, NJ304-ECP, NJ304EA, NU304, NU304EA, NUP304-ECP, NUP304EA, QJ-304-MA, QJ-304-N2MA, QJ-304-N2PHAS, W6304, W6304-2RS, W6304-ZZ.

Frequently asked questions

Are all 20×52×15 mm bearings interchangeable?

They share the same ISO 15 boundary dimensions — 20 mm bore, 52 mm OD, 15 mm width (0.787×2.047×0.591 in) — so they fit the same shaft, housing bore and axial space. Interchangeability ends at the envelope: dynamic load rating, seal arrangement, internal clearance, cage and precision class differ between the 43 models listed here and must be checked against the duty before substitution.

Is it a drop-in replacement if two bearings both measure 20×52×15?

Only after verification. Confirm five things in order: (1) the C/C0 load ratings meet the original life calculation, (2) the seal type is equivalent or acceptable for the contamination level (open vs -ZZ vs -2RS), (3) internal clearance matches (CN/C3/C4 — an interference fit changes residual play), (4) cage material and precision class suit the speed, and (5) the axial-locating behaviour is the same (for example an NU cylindrical roller floats while an NJ locates one way). Same dimensions alone never guarantee equal performance.

What is 20×52×15 mm in inches?

20×52×15 mm converts to 0.787×2.047×0.591 in, with a 16 mm (0.630 in) radial section height. These are the ISO 15 general-plan envelope dimensions shared across manufacturers, which is why models such as 1304, 1304-ETN9, 1304K mount in the same space despite different internal designs.