Datasheet

Table 2
Radial internal clearance
Bore diameter Radial internal clearance
d C2 Normal C3 C4
over incl. min max min max min max min max
mm µm
– 9,525 3 8 5 10 8 13 13 20
10 10 0 7 2 13 8 23 14 29
10 18 0 9 3 18 11 25 18 33
18 24 1 10 5 20 13 28 20 36
24 30 1 11 5 20 13 28 23 41
30 40 1 11 6 20 15 33 28 46
40 50 1 11 6 23 18 36 30 51
50 65 1 15 8 28 23 43 38 61
65 80 1 15 10 30 25 51 46 71
Bearing data – general
Dimensions
The boundary dimensions of metric stain-
less steel deep groove ball bearings conform
to ISO 15-1998, except for bearings with
a WBB1 prefix or an X suffix. Inch series
stainless steel deep groove ball bearings
conform to ANSI/AFBMA Std. 12.2-1992.
Tolerances
All stainless steel deep groove ball bearings
are manufactured as standard to Normal
tolerances corresponding to ISO 492-2002.
Internal clearance
SKF stainless steel deep groove ball bearings
are manufactured as standard with Normal
radial internal clearance to ISO 5753-1991,
except for bore diameters < 10 mm
(† table 2). Other classes are available
upon request. The values for radial internal
clearance given in table 2 are valid for un-
mounted bearings under zero measuring
load.
Misalignment
SKF stainless steel deep groove ball bearings
have only a limited ability to accomodate
misalignment. The permissible angular mis-
alignment between inner and outer rings
which will not produce inadmissibly high
additonal stresses in the bearing depends
on the radial internal clearance of the bearing
in operation, bearing size, the internal design
and the forces and moments acting on the
bearing. In other words, depending on the
various influencing factors, the permissible
angular misalignment lies between 2 and
10 minutes of arc. Any misalignment will
increase bearing noise and reduce bearing
service life. For additional information, contact
the SKF application engineering service.
Minimum load
For satisfactory operation, SKF stainless
steel deep groove ball bearings must always
be subjected to a given minimum load.
The requisite minimum radial load to be
applied to SKF stainless steel deep groove
ball bearings can be estimated using
q n n
w
2/3
q d
m
w
2
F
rm
= k
r
–—— ——
< 1 000 z < 100 z
where
F
rm
= minimum radial load [kN]
k
r
= minimum load factor
n = oil viscosity at operating
temperature [mm
2
/s]
n = rotational speed [r/min]
d
m
= bearing mean diameter
= 0,5 (d + D) [mm]
When starting up at low temperatures or
when the lubricant is highly viscous, even
greater minimum loads may be required.
The weight of the compoments supported
by the bearing, together with external forces,
generally exceeds the requisite minimum
load. If this is not the case, the bearing must
be subjected to an additional radial load.
For applications where stainless steel deep
groove ball bearings are used, an axial pre-
load can be applied by adjusing the inner
and outer rings against each other or by
using springs.
Axial load carrying capacity
SKF stainless steel deep groove ball bearings
have the same axial load carrying capacity
as standard SKF deep groove ball bearings.
If they are subjected to purely axial loads,
this load should generally not exceed the
value of 0,25 C
0
. Excessive axial load can
lead to a reduction in bearing service life.
Equivalent bearing loads
Equivalent bearing loads for SKF stainless
steel deep groove ball bearings can be cal-
culated the same way as for standard SKF
deep groove ball bearings. For additional
information, contact the SKF application
engineering service.
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