321 is a NSK cylindrical roller bearing, bore 105 mm, O.D. 225 mm, width 49 mm, dynamic rating 71,500 lbs. Dimensions, drawing, interchanges and price.
Original catalogue drawing - NSK catalogue, page 55
Scanned from the manufacturer catalogue page listing this part number. All part numbers printed on that table share the same drawing.
Scale cross-section
Blue = inner / outer ring, yellow = rolling element. Drawn to scale from this part's own
dimensions for selection reference only - not a manufacturing or assembly drawing.
Dimension table (mm / inch)
Symbol
Dimension
mm
inch
d
Bore diameter
105
4.1339
D
Outside diameter
225
8.8583
B
Inner-ring / bearing width
49
1.9291
Notes
Cylindrical roller entries from the NSK inch catalogue are series numbers covering the N / NU / NJ / NUP / NH prefixes of the same size. Weights are given in kg. Load ratings are shown in both the original catalogue units and the converted value (1 N = 0.2248 lbf). Data is provided for selection reference only - confirm against the latest official catalogue before ordering.
Main dimensions
Bore d (mm)
105
Bore d (in)
4.1339
Outside dia. D (mm)
225
Outside dia. D (in)
8.8583
Width B (mm)
49
Width B (in)
1.9291
Load ratings & speeds
Basic dynamic load rating Cr (lbs)
71500
Basic static load rating Cor (lbs)
80300
Limiting speed - grease (rpm)
2,600
Limiting speed - oil (rpm)
3,200
Weight
Weight (kg)
8.618
Mounting dimensions (fillets / shoulders)
Fillet ra max (in)
0.099
Fillet rb max (in)
0.098
Shaft shoulder da min (in)
4.646
Housing shoulder Da max (in)
8.307
Shaft shoulder db min (in)
4.764
Shaft shoulder db max (in)
5.157
Housing shoulder Db min (in)
7.835
Housing shoulder Db max (in)
8.346
Bearing life (ISO 281 basic rating life)
C / P
Equivalent load P (N)
L10 (106 rev)
L10h at 800 rpm
4
79,512
102
2,117
6
53,008
392
8,177
8
39,756
1,024
21,333
10
31,805
2,154
44,884
15
21,203
8,323
173,406
Basic rating life per ISO 281: L10 = (C/P)10/3 with C = 318,048 N. Hours = L10 x 106 / (60n). Life-modification factors for lubrication, contamination and temperature (aISO) are not included.
Source & traceability
Brand
NSK
Source catalogue
NSK inch product catalogue
Catalogue page
p.57 (dimensions) / p.58 (ratings)
Dimensions in inches and millimetres, load ratings in lbs.
Send us the quantity you need and we will come back with price and
lead time, normally within 24 hours. Equivalent parts from other brands can be quoted at the same time.
