The dimensional and running accuracy of rolling bearings has been standardized internationally (Bearing tolerance). The tolerance symbols and their definitions are provided in table as blow:
Tolerance symbol 
Definition 
Radial bearings inner ring  cylindrical and tapered bore  
d 

Δdmp 

Δds  Deviation of a twopoint size of bore diameter of a cylindrical bore from its nominal size 
Vdsp  Range of twopoint sizes of bore diameter in any cross section of a cylindrical or tapered bore 
Vdmp  Range of midrange sizes (out of twopoint sizes) of bore diameter obtained from any cross section of a cylindrical bore 
B  Nominal inner ring width 
ΔBs Normal, Modified1) 

VBs 

Kia  Circular radial runout of inner ring bore surface of assembled bearing with respect to datum, i.e. axis, established from the outer ring outside surface 
Sd  Circular axial runout of inner ring face with respect to datum, i.e. axis, established from the inner ring bore surface 
Sia  Circular axial runout of inner ring face of assembled bearing with respect to datum, i.e. axis, established from the outer ring outside surface 
Radial bearings inner ring  tapered bore only  
d1  Nominal bore diameter at the theoretical large end of a tapered bore 
Δd1mp  Deviation of a midrange size (out of twopoint sizes) of bore diameter at the theoretical large end from its nominal size 
SL  Taper slope, the difference between nominal diameters at the theoretical large end and small end of a tapered bore (d1  d) 
ΔSL  Deviation of taper slope of a tapered inner ring bore from its nominal size 
Radial bearings outer ring  
D  Nominal outside diameter 
ΔDmp  Deviation of a midrange size (out of twopoint sizes) of outside diameter in any cross section from its nominal size 
ΔDs  Deviation of a twopoint size of outside diameter from its nominal size 
VDsp  Range of twopoint sizes of outside diameter in any cross section 
VDmp  Range of midrange sizes (out of twopoint sizes) of outside diameter obtained from any cross section 
C  Nominal outer ring width 
ΔCs Normal, Modified1) 

VCs 

Kea  Circular radial runout of outer ring outside surface of assembled bearing with respect to datum, i.e. axis, established from the inner ring bore surface 
SD  Perpendicularity of outer ring outside surface axis with respect to datum established from the outer ring face 
Sea  Circular axial runout of outer ring face of assembled bearing with respect to datum, i.e. axis, established from the inner ring bore surface 
Chamfer limits  
rs  Single chamfer dimension 
rs min  Smallest single chamfer dimension of rs, r1, r2, r3, r4 … 
r1, r3  Radial direction chamfer dimensions 
r2, r4  Axial direction chamfer dimensions 
Tapered roller bearings  
T  Nominal assembled bearing width 
ΔTs  Deviation of minimum circumscribed size of assembled bearing width from its nominal size 
T1  Nominal effective width of cone (inner ring, with roller and cage assembly) assembled with a master cup (outer ring) 
T2  Nominal effective width of cup assembled with a master cone 
ΔT1s  Deviation of minimum circumscribed size of effective width (cone assembled with a master cup) from its nominal size 
ΔT2s  Deviation of minimum circumscribed size of effective width (cup assembled with a master cone) from its nominal size 
Thrust bearings shaft washer  
d  Nominal bore diameter of shaft washer, single direction bearing 
Δds  Deviation of a twopoint size of shaft washer bore diameter from its nominal size 
Δdmp  Deviation of a midrange size (out of twopoint sizes) of shaft washer bore diameter in any cross section from its nominal size 
Vdsp  Range of twopoint sizes of shaft washer bore diameter in any cross section 
d2  Nominal bore diameter of central shaft washer, double direction bearing 
Δd2mp  Deviation of a midrange size (out of twopoint sizes) of central shaft washer bore diameter in any cross section from its nominal size 
Vd2sp  Range of twopoint sizes of central shaft washer bore diameter in any cross section 
Si 

Thrust bearings housing washer  
D  Nominal outside diameter of housing washer 
ΔDs  Deviation of a twopoint size of housing washer outside diameter from its nominal size 
ΔDmp  Deviation of a midrange size (out of twopoint sizes) of housing washer outside diameter in any cross section from its nominal size 
VDsp  Range of twopoint sizes of housing washer outside diameter in any cross section 
Se 

Thrust bearings assembled bearing height  
T  Nominal assembled bearing height, single direction thrust bearing (except spherical roller thrust bearing → T4) 
ΔTs  Deviation of minimum circumscribed size of assembled bearing height from its nominal size, single direction thrust bearing (except spherical roller thrust bearing → ΔT4s) 
T1 

ΔT1s 

T32)  Nominal assembled bearing height, double direction thrust bearing with seat washers 
ΔT3s2)  Deviation of minimum circumscribed size of assembled bearing height from its nominal size, double direction thrust bearing with seat washers 
T43)  Nominal assembled bearing height, spherical roller thrust bearing 
ΔT4s3)  Deviation of minimum circumscribed size of assembled bearing height from its nominal size, spherical roller thrust bearing 
 1) Modified applies to inner rings and outer rings of bearings of matched bearing sets consisting of two or more bearings. Does not apply to universally matchable angular contact ball bearings.
 2) Not included in ISO 199:2014.
 3) In ISO 199:2014, the symbol T is used.