256 is a NSK cylindrical roller bearing, bore 280 mm, O.D. 500 mm, width 80 mm, dynamic rating 257,000 lbs. Dimensions, drawing, interchanges and price.
Original catalogue drawing - NSK catalogue, page 53
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
280
11.0236
D
Outside diameter
500
19.685
B
Inner-ring / bearing width
80
3.1496
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)
280
Bore d (in)
11.0236
Outside dia. D (mm)
500
Outside dia. D (in)
19.6850
Width B (mm)
80
Width B (in)
3.1496
Load ratings & speeds
Basic dynamic load rating Cr (lbs)
257000
Basic static load rating Cor (lbs)
376000
Limiting speed - grease (rpm)
1,100
Limiting speed - oil (rpm)
1,400
Weight
Weight (kg)
70.307
Mounting dimensions (fillets / shoulders)
Fillet ra max (in)
0.157
Fillet rb max (in)
0.157
Shaft shoulder da min (in)
13.150
Housing shoulder Da max (in)
18.898
Shaft shoulder db min (in)
11.811
Shaft shoulder db max (in)
13.150
Housing shoulder Db min (in)
17.638
Housing shoulder Db max (in)
18.898
Bearing life (ISO 281 basic rating life)
C / P
Equivalent load P (N)
L10 (106 rev)
L10h at 300 rpm
4
285,798
102
5,644
6
190,532
392
21,805
8
142,899
1,024
56,889
10
114,319
2,154
119,691
15
76,213
8,323
462,415
Basic rating life per ISO 281: L10 = (C/P)10/3 with C = 1,143,193 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.55 (dimensions) / p.56 (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.
