NTN 306-Z

Deep groove ball · 2Z shield

The seat — 30 MM × 72 MM × 19 MM

Bore

30 MM

Outside dia

72 MM

Width

19 MM

Type

Deep groove ball

Seal

2Z shield

Clearance

CN (Normal)

Precision

ABEC-1 (P0)

Dynamic C

29.7 kN

Static C0

21.6 kN

144 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 — 19 designations

Part number	Manufacturer	C	C0
6306.2ZR	FAG (Schaeffler)	29.9 kN	16.2 kN
6406.2ZR	FAG (Schaeffler)	29.9 kN	16.2 kN
306-2Z	NTN	29.7 kN	21.6 kN
306-2ZNR	NTN	29.7 kN	21.6 kN
306KDD	Timken	29.6 kN	16.0 kN
6306-2Z	NTN	29.6 kN	16.0 kN
6306-2Z/GJN	NTN	29.6 kN	16.0 kN
6306-2ZNR	NTN	29.6 kN	16.0 kN
6306-Z	NTN	29.6 kN	16.0 kN
6306 2ZJEM	NTN	29.6 kN	16.0 kN
6306 2ZNRJEM	NTN	29.6 kN	16.0 kN
6306ZZ	NTN	29.6 kN	16.0 kN
6406-2Z	NTN	29.6 kN	16.0 kN
MRC.306SZZ	NTN	29.6 kN	16.0 kN
MRC.306SZZG	NTN	29.6 kN	16.0 kN
6406ZZ	NTN	28.7 kN	15.5 kN
W 6306-2Z	NTN	22.9 kN	15.0 kN
6306-2Z/VA208	NTN	—	16.0 kN
6306-2Z/VA228	NTN	—	16.0 kN

Check before substituting — 125 designations · top 12 shown

Part number	Manufacturer	C	Differs from this part
21306 CC	NTN	65.7 kN	Type: Spherical — this part: Deep groove ball Seal: Open — this part: 2Z shield
21306 CC/C3	NTN	65.7 kN	Type: Spherical — this part: Deep groove ball Seal: Open — this part: 2Z shield Clearance: C3 — this part: CN (Normal)
N 306 ECP	NTN	58.5 kN	Type: Cylindrical — this part: Deep groove ball Seal: Open — this part: 2Z shield
NJ 306 ECJ	NTN	58.5 kN	Type: Cylindrical — this part: Deep groove ball Seal: Open — this part: 2Z shield
NJ 306 ECJ/C3	NTN	58.5 kN	Type: Cylindrical — this part: Deep groove ball Seal: Open — this part: 2Z shield Clearance: C3 — this part: CN (Normal)
NJ 306 ECM	NTN	58.5 kN	Type: Cylindrical — this part: Deep groove ball Seal: Open — this part: 2Z shield
NJ 306 ECML	NTN	58.5 kN	Type: Cylindrical — this part: Deep groove ball Seal: Open — this part: 2Z shield
NJ 306 ECP	NTN	58.5 kN	Type: Cylindrical — this part: Deep groove ball Seal: Open — this part: 2Z shield
NJ 306 ECP/C3	NTN	58.5 kN	Type: Cylindrical — this part: Deep groove ball Seal: Open — this part: 2Z shield Clearance: C3 — this part: CN (Normal)
NJ 306 ECP/C4	NTN	58.5 kN	Type: Cylindrical — this part: Deep groove ball Seal: Open — this part: 2Z shield Clearance: C4 — this part: CN (Normal)
NU 306 ECJ	NTN	58.5 kN	Type: Cylindrical — this part: Deep groove ball Seal: Open — this part: 2Z shield
NU 306 ECJ/C3	NTN	58.5 kN	Type: Cylindrical — this part: Deep groove ball Seal: Open — this part: 2Z shield 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/306-Z/SUBSTITUTE