NACHI 6321-NR Bearing — Specifications, Dimensions & Cross-Reference

The NACHI 6321-NR is a deep groove ball bearing with snap ring groove manufactured by NACHI. It belongs to the 6300 series and features dimensions of 105 × 225 × 49 mm (bore × OD × width). This bearing has a dynamic load rating of 182,000 N and a static load rating of 153,000 N, making it suitable for heavy-duty applications.

Technical Specifications

Dimensions
Bore Diameter (d)105 mm
Outside Diameter (D)225 mm
Width (B)49 mm
Weight7.200 kg
Performance
Dynamic Load Rating (Cr)182,000 N
Static Load Rating (C₀r)153,000 N
Limiting Speed (Grease)2,800 rpm
Limiting Speed (Oil)3,400 rpm
💡 Application Note: The 6300 series bearings are commonly used in heavy-duty electric motors, mining equipment, construction machinery, and industrial gearboxes. The -NR suffix indicates an external snap ring groove on the outer ring, allowing easy axial location in housing bores.

Brand Cross-Reference — 6321-NR Equivalents

The following bearings from other manufacturers are interchangeable with the NACHI 6321-NR. All share identical dimensions (105×225×49mm) and comparable load ratings:

BrandPart NumberDynamic Load (N)Static Load (N)
NACHINACHI 6321-NR ✦182,000153,000
Timken Timken 6321-NR 182,000 153,000
SKF SKF 6321-NR 182,000 153,000
NTN NTN 6321-NR 182,000 153,000
KOYO KOYO 6321-NR 182,000 153,000
FAG FAG 6321-NR 182,000 153,000
Timken Timken 6321-NR 182,000 153,000
NSK NSK 6321-NR 182,000 153,000
NTN NTN 6321-NR 182,000 153,000
SKF SKF 6321-NR 182,000 153,000

Available Variants

The NACHI 6321 base bearing is available in these configurations:

NACHI 6321-ZZ-C3
"Double shielded
NACHI 6321-ZZ
Double metal shielded
NACHI 6321-2Z
Double metal shielded (ISO)
NACHI 6321-2RS-C3
"Double sealed
NACHI 6321-2RS
Double rubber sealed
NACHI 6321
Open (no seal/shield)

Frequently Asked Questions

What are the dimensions of the NACHI 6321-NR?

The NACHI 6321-NR has a bore diameter of 105mm, outside diameter of 225mm, and width of 49mm. It weighs 7.200kg.

What is the load capacity of the NACHI 6321-NR?

The dynamic load rating (Cr) is 182,000 N and the static load rating (C₀r) is 153,000 N. The maximum recommended speed is 2,800 rpm with grease lubrication or 3,400 rpm with oil lubrication.

What bearings are equivalent to NACHI 6321-NR?

The 6321-NR is manufactured by multiple brands including SKF, NTN, NSK, FAG, Timken, KOYO, and NACHI. All versions share the same 105×225×49mm dimensions and are interchangeable in most applications. See the cross-reference table above for detailed comparisons.