MPNbase

120×260×55 mm bearings

27 models from 3 brands across 3 types share this ISO 15 envelope: 120 mm bore, 260 mm outside diameter, 55 mm width (4.724×10.236×2.165 in), 70 mm radial section.

27 models fit this space 3 brands 27 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)
6324 Deep Groove Ball SKF open CN 208 186 12500
6324-2RS Deep Groove Ball SKF 2RS CN 208 186 12500
6324-2RS-NSK Deep Groove Ball NSK 2RS CN 227 185 12500
6324-2RS-NTN Deep Groove Ball NTN 2RS CN 229 185 12400
6324-M Deep Groove Ball SKF open CN 208 186 14000
6324-NSK Deep Groove Ball NSK open CN 227 185 12500
6324-NTN Deep Groove Ball NTN open CN 229 185 12400
6324-ZZ Deep Groove Ball SKF ZZ CN 208 186 12500
6324-ZZ-NSK Deep Groove Ball NSK ZZ CN 227 185 12500
6324-ZZ-NTN Deep Groove Ball NTN ZZ CN 229 185 12400
7324 Angular Contact Ball NTN open CN 273 252 14700
7324-BCBM Angular Contact Ball SKF open CN 238 250 14500
7324B Angular Contact Ball NTN open CN 249 231 14700
N324 Cylindrical Roller NTN open CN 500 510 12500
N324-ECP Cylindrical Roller SKF open CN 610 620 13000
NF324 Cylindrical Roller NTN open CN 500 510 12500
NJ324 Cylindrical Roller NTN open CN 500 510 12500
NJ324-ECJ Cylindrical Roller SKF open CN 610 620 13500
NJ324E Cylindrical Roller NTN open CN 585 610 —
NU324 Cylindrical Roller NTN open CN 500 510 12500
NU324-ECP Cylindrical Roller SKF open CN 610 620 13000
NU324E Cylindrical Roller NTN open CN 585 610 —
NUP324 Cylindrical Roller NTN open CN 500 510 12500
NUP324-ECP Cylindrical Roller SKF open CN 610 620 14000
NUP324E Cylindrical Roller NTN open CN 585 610 —
QJ-324-N2MA Angular Contact Ball SKF open CN 415 530 16000
QJ324 Angular Contact Ball NTN open CN 360 765 15900

Note: catalogue dynamic load ratings for this envelope span 208.0– 610.0 kN — a 193% spread between designs in the very same 120×260×55 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 120 mm bore bearings for wider or narrower sections, or open a model page for naming-rule decode, applications and graded cross references: 6324, 6324-2RS, 6324-2RS-NSK, 6324-2RS-NTN, 6324-M, 6324-NSK, 6324-NTN, 6324-ZZ, 6324-ZZ-NSK, 6324-ZZ-NTN, 7324, 7324-BCBM, 7324B, N324, N324-ECP, NF324, NJ324, NJ324-ECJ, NJ324E, NU324, NU324-ECP, NU324E, NUP324, NUP324-ECP, NUP324E, QJ-324-N2MA, QJ324.

Frequently asked questions

Are all 120×260×55 mm bearings interchangeable?

They share the same ISO 15 boundary dimensions — 120 mm bore, 260 mm OD, 55 mm width (4.724×10.236×2.165 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 27 models listed here and must be checked against the duty before substitution.

Is it a drop-in replacement if two bearings both measure 120×260×55?

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 120×260×55 mm in inches?

120×260×55 mm converts to 4.724×10.236×2.165 in, with a 70 mm (2.756 in) radial section height. These are the ISO 15 general-plan envelope dimensions shared across manufacturers, which is why models such as 6324, 6324-2RS, 6324-2RS-NSK mount in the same space despite different internal designs.