Radial Ball Bearings Radial Ball Bearings - Rainbow Precision ...

To ensure dimensional accuracy in measurable
forms, all PEER bearings are manufactured
according to the ABMA established classes. These
are currently listed as ABEC-1, 3, 5 and 7 for ball
bearings. All standard production PEER bearings
are manufactured to a minimum of ABEC-1
tolerances. The higher the ABEC number, the higher
the precision class.
ABEC-1 and 3 specify inner ring tolerances for
∆dmp, Vdp, Vdmp, Kia, ∆Bs, VBS. And outer ring
tolerances of ∆Dmp, VDp, VDmp, Kea, ∆cs, Vcs.
See Tables 2 through 5.
ABEC-5 specifies tolerances for the same
characteristics as classes 1 and 3 with the addition
of Sd and Sia for the inner ring and SD and Sea for
the outer ring.
See “Tolerance Definitions” for an explanation of
these symbols.
TOLERANCE DEFINITIONS
ABMA Std. 20-1996
Bore Diameter
d Nominal bore diameter
ds Single bore diameter
∆ds =ds-d
Deviation of a single bore diameter from
nominal dimension
dpsmax Single plane maximum
dpsmin Single plane minimum bore diameter
dmp = dpsmax + dpsmin
2
Single plane mean bore diameter
∆dmp =dmp - d
Single plane mean bore diameter deviation
Vdp
=dpsmax - dmpmin
Bore diameter variation in a single radial
plane
Vdmp =dmpmax - dmpmin
Means bore diameter variation; difference
between maximum and minimum mean
diameter
Outside Diameter
D Nominal outside diameter
ENGINEERING DATA
BEARING TOLERANCES AND PRECISION
54
Ds Single outside diameter
∆Ds =Ds - D
Deviation of a single outside diameter from
nominal dimensions
Dpsmax Single plane maximum outside diameter
Dpsmin Single plane minimum diameter
Dmp = Dpsmax + Dpsmin
2
Single plane means outside diameter
∆Dmp =Dmp - D
Single plane means outside diameter
deviation
VDp
=Dpsmax - Dpsmin
Outside diameter variation in a single radial
plane
VDmp =Dmpmax - Dmpmin
Means outside diameter variation;
difference between maximum and minimum
mean outside diameter
Width
B Nominal inner ring width
C Nominal outer ring width
Single ring width (inner, outer ring)
BsCs
∆Bs, ∆Cs=Bs - B, Cs - C
Deviation of a single ring width (inner, outer
ring) from nominal
VBs, CCs=Bsmax - Bsmin, Csmax - Csmin
Variation of inner and outer ring width
Running Accuracy
Kia Inner ring radial runout of assembled
bearing
Kea Outer ring radial runout of assembled
bearing
Sd Inner ring face runout to bore
SD Outer ring outside diameter surface runout
to face
Sia Inner ring face runout to raceway of
assembled bearing
Sea Outer ring face runout to raceway of
assembled bearing