ball and roller bearings - NTN Bearing Corporation of America

TOLERANCE
TABLES
254
TOLERANCES
Definitions pertaining to tolerance limits for boundary dimensions, various runouts, and internal clearance are
given in AFBMA Standard 4, ANSI B3.4: Tolerance Definitions and Gaging Practice. The tolerance limits listed
in this Standard refer exclusively to these concepts.
d =
SYMBOLS COMMON TO RADIAL BEARINGS AND THRUST BEARINGS
Basic bore diameter
D = Basic outside diameter
Vdp = Single radial plane bore diameter variation
VDp = Single radial plane outside diameter variation
ra max = Largest shaft and housing fillets which the bearing chamfer must clear
rs = Single chamfer dimension of a ring
rs min = Low limit of r
rs max = High limit of r
B =
SYMBOLS APPLICABLE TO RADIAL BEARINGS
Basic width of an individual inner ring; also of an individual outer ring when
both rings have the same basic width
Bs = Single width of an inner ring; also that of an outer ring when both rings have
the same basic width
Vdmp = Mean single plane bore diameter variation
VDmp = Single plane mean outside diameter deviations
K1 = Radial runout of an inner ring raceway
Ke = Radial runout of an outer ring raceway
Sd = Reference side runout with bore of an inner ring
SD = Outside cylindrical surface runout with reference side of an outer ring
Sia = Assembled bearing inner ring (or cone back face) runout with raceway
Sea = Assembled bearing outer ring (or cup back face) runout with raceway
VBs = Width variation of an inner ring; also that of an outer ring when both rings have
the same basic width
H =
SYMBOLS APPLICABLE TO SINGLE DIRECTION THRUST BEARINGS
Basic bearing height
Hm = Actual bearing height
Ai = Raceway runout with flat seat face of shaft washer
Ae = Raceway runout with flat seat face of housing washer