NTN 6304 Bearing — Specifications, Dimensions & Cross-Reference

The NTN 6304 is a deep groove ball bearing manufactured by NTN. It belongs to the 6300 series and features dimensions of 20 × 52 × 15 mm (bore × OD × width). This bearing has a dynamic load rating of 15,900 N and a static load rating of 7,800 N, making it suitable for medium-duty applications.

Technical Specifications

Dimensions
Bore Diameter (d)20 mm
Outside Diameter (D)52 mm
Width (B)15 mm
Weight0.138 kg
Performance
Dynamic Load Rating (Cr)15,900 N
Static Load Rating (C₀r)7,800 N
Limiting Speed (Grease)13,000 rpm
Limiting Speed (Oil)16,000 rpm
💡 Application Note: The 6300 series bearings are commonly used in heavy-duty electric motors, mining equipment, construction machinery, and industrial gearboxes.

Brand Cross-Reference — 6304 Equivalents

The following bearings from other manufacturers are interchangeable with the NTN 6304. All share identical dimensions (20×52×15mm) and comparable load ratings:

BrandPart NumberDynamic Load (N)Static Load (N)
NTNNTN 6304 ✦15,9007,800
Timken Timken 6304 15,900 7,800
SKF SKF 6304 15,900 7,800
NTN NTN 6304 15,900 7,800
NACHI NACHI 6304 15,900 7,800
KOYO KOYO 6304 15,900 7,800
FAG FAG 6304 15,900 7,800
Timken Timken 6304 15,900 7,800
NSK NSK 6304 15,900 7,800
SKF SKF 6304 15,900 7,800

Available Variants

The NTN 6304 base bearing is available in these configurations:

NTN 6304-ZZ-C3
"Double shielded
NTN 6304-ZZ
Double metal shielded
NTN 6304-NR
Open with snap ring
NTN 6304-C3
"Open
NTN 6304-2Z
Double metal shielded (ISO)
NTN 6304-2RS-C3
"Double sealed
NTN 6304-2RS
Double rubber sealed
NTN 6304
Open (no seal/shield)
NTN 6304-NR
Open with snap ring
NTN 6304-ZZ-C3
Double shielded, C3 clearance
NTN 6304-2RS-C3
Double sealed, C3 clearance
NTN 6304-C3
Open, C3 clearance
NTN 6304-2Z
Double metal shielded (ISO)
NTN 6304-ZZ
Double metal shielded
NTN 6304-2RS
Double rubber sealed

Frequently Asked Questions

What are the dimensions of the NTN 6304?

The NTN 6304 has a bore diameter of 20mm, outside diameter of 52mm, and width of 15mm. It weighs 0.138kg.

What is the load capacity of the NTN 6304?

The dynamic load rating (Cr) is 15,900 N and the static load rating (C₀r) is 7,800 N. The maximum recommended speed is 13,000 rpm with grease lubrication or 16,000 rpm with oil lubrication.

What bearings are equivalent to NTN 6304?

The 6304 is manufactured by multiple brands including SKF, NTN, NSK, FAG, Timken, KOYO, and NACHI. All versions share the same 20×52×15mm dimensions and are interchangeable in most applications. See the cross-reference table above for detailed comparisons.