NTN 309 NR

Deep groove ball · Open

The seat — 45 MM × 100 MM × 25 MM

Bore

45 MM

Outside dia

100 MM

Width

25 MM

Type

Deep groove ball

Seal

Open

Clearance

CN (Normal)

Precision

ABEC-1 (P0)

Dynamic C

55.0 kN

Static C0

44.0 kN

164 other designations in the catalogue share this bore × outside diameter × width. Each was compared on the four fields every bearing row carries — Type, Seal, Clearance, Precision — as recorded, case- and separator-insensitively. All four agreeing puts a designation in the first list; anything else, a difference or a blank, puts it in the second with the fields named.

Candidates at the recorded dimensions above

May substitute — 26 designations · top 20 shown

Part number	Manufacturer	C	C0
6309-ZNR	NTN	55.3 kN	31.5 kN
6309 JEM	NTN	55.3 kN	31.5 kN
6309 M	NTN	55.3 kN	31.5 kN
6309 N	NTN	55.3 kN	31.5 kN
6309 NR	NTN	55.3 kN	31.5 kN
6309 NRJEM	NTN	55.3 kN	31.5 kN
6309 RSJEM	NTN	55.3 kN	31.5 kN
6309 ZJEM	NTN	55.3 kN	31.5 kN
6309 ZNRJEM	NTN	55.3 kN	31.5 kN
MRC.309S	NTN	55.3 kN	31.5 kN
MRC.309SF	NTN	55.3 kN	31.5 kN
MRC.309SFF	NTN	55.3 kN	31.5 kN
MRC.309SG	NTN	55.3 kN	31.5 kN
309	NTN	55.0 kN	44.0 kN
309-ZNR	NTN	55.0 kN	44.0 kN
MRC.309M	NTN	55.0 kN	44.0 kN
MRC.309MF	NTN	55.0 kN	44.0 kN
MRC.309MFF	NTN	55.0 kN	44.0 kN
MRC.309MFG	NTN	55.0 kN	44.0 kN
MRC.309MG	NTN	55.0 kN	44.0 kN

Check before substituting — 138 designations · top 12 shown

Part number	Manufacturer	C	Differs from this part
21309 E	NTN	129.0 kN	Type: Spherical — this part: Deep groove ball
21309 E/C3	NTN	129.0 kN	Type: Spherical — this part: Deep groove ball Clearance: C3 — this part: CN (Normal)
21309 EK	NTN	129.0 kN	Type: Spherical — this part: Deep groove ball
21309 EK/C3	NTN	129.0 kN	Type: Spherical — this part: Deep groove ball Clearance: C3 — this part: CN (Normal)
N 309 ECP	NTN	112.0 kN	Type: Cylindrical — this part: Deep groove ball
NJ 309 ECJ	NTN	112.0 kN	Type: Cylindrical — this part: Deep groove ball
NJ 309 ECJ/C3	NTN	112.0 kN	Type: Cylindrical — this part: Deep groove ball Clearance: C3 — this part: CN (Normal)
NJ 309 ECM	NTN	112.0 kN	Type: Cylindrical — this part: Deep groove ball
NJ 309 ECML	NTN	112.0 kN	Type: Cylindrical — this part: Deep groove ball
NJ 309 ECML/C3	NTN	112.0 kN	Type: Cylindrical — this part: Deep groove ball Clearance: C3 — this part: CN (Normal)
NJ 309 ECP	NTN	112.0 kN	Type: Cylindrical — this part: Deep groove ball
NJ 309 ECP/C3	NTN	112.0 kN	Type: Cylindrical — this part: Deep groove ball Clearance: C3 — this part: CN (Normal)

What this sheet is — and what the catalogue did not say

The envelope is recorded dimensions only: the same bore, outside diameter and width. Every designation above shares all three, or it would not be on this page.
The four compared fields are Type, Seal, Clearance, Precision. Two recorded spellings were counted to mean one value and are read as one: CN/Normal = CN, and ABEC-1/P0 = P0. A third precision spelling, P0/Class4, is deliberately not equated with either — the catalogue's meaning for it has not been sourced, so it lands in the warnings where both spellings are printed for the reader to judge.
A blank is a difference. Missing is the absence of the proof, not the proof.
Cage material and ring material are never compared: the catalogue records neither, on any bearing row.
Suffixes the catalogue does not record separately — a snap ring (NR) and anything else outside those four fields — are not compared, and this sheet does not claim they match.
Ranking is recorded dynamic load, strongest first, with an unrecorded rating ranked last. It orders the lists; it is not a verdict.
Compiled from catalogue records. This is not a manufacturer interchange list, no manufacturer has confirmed any line on it, and it does not know what job the bearing is doing. Verify before fitting.

Anyone with this link can view this part and its recorded candidate comparison.

BEARINGBRAIN.COM/PART/309NR/SUBSTITUTE