NTN bearing tolerances

NTN bearing “tolerances” or dimensional accuracy and running accuracy, are regulated by ISO and JIS B 1514 standards (rolling bearing tolerances). For dimensional accuracy, these standards prescribe the tolerances necessary when installing bearings on shafts or in housings. Running accuracy is defined as the allowable limits for bearing runout during operation.

Dimensional accuracy
Dimensional accuracy constitutes the acceptable values for bore diameter, outer diameter, assembled bearing width, and bore diameter uniformity as seen in chamfer dimensions, allowable inner ring tapered bore deviation and shape error. Also included are, average bore diameter variation, outer diameter variation, average outer diameter unevenness, as well as raceway width and height variation (for thrust bearings).

Running accuracy
Running accuracy constitutes the acceptable values for inner and outer ring radial runout and axial runout, inner ring side runout, and outer ring outer diameter runout.

Allowable rolling bearing tolerances have been established according to precision classes. Bearing precision is stipulated as JIS class 6, class 5, class 4, or class 2, with precision rising from ordinary precision indicated by class 0.

NTN bearing types and applicable tolerance
Bearing type Applicable standard Tolerance class Tolerance table
NTN Deep groove ball bearings JIS B 1514
(ISO492)
class 0 class 6 class 5 class 4 class 2 tolerances for radial bearings
(normal, P6, P5)
Angular contact ball bearings class 0 class 6 class 5 class 4 class 2
Self-aligning ball bearings class 0 - - - -
Cylindrical roller bearigns class 0 class 6 class 5 class 4 class 2
Needle roller bearings class 0 class 6 class 5 class 4 -
Spherical roller bearings class 0 - - - -
NTN Tapered roller bearings metric JIS B 1514 class 0,6X class 6 class 5 class 4 - Tolerance of tapered roller bearings
Inch ANSI/ABMA Std.19 class 4 class 2 class 3 class 0 class 00  
J series ANSI/ABMA Std.19.1 class K class N class C class B class A  
Thrust ball bearings JIS B 1514
(ISO199)
class 0 class 6 class 5 class 4 - Tolerance of thrust ball bearings
Spherical roller thrust bearings class 0 - - - -  


Comparison of tolerance classifications of national standards
Standard Applicable standerd Tolerance Class Bearing Types
Japanese industrial standard (JIS) JIS B 1514 Class 0,6X Class 6 Class 5 Class 4 Class 2 All type
International Organization for Standardization (ISO) ISO 492 Normal class Class 6X Class 6 Class 5 Class 4 Class 2 Radial bearings
ISO 199 Normal Class Class 6 Class 5 Class 4 - Thrust ball bearings
ISO 578 Class 4 - Class 3 Class 0 Class 00 Tapered roller bearings (Inch series)
ISO 1224 - - Class 5A Class 4A - Precision instrument bearings
Deutsches Institut fur Normung(DIN) DIN 620 P0 P6 P5 P4 P2 All type
American National Standards Institute (ANSI) ANSI/ABMA Std.20 ABEC-1
RBEC-1
ABEC-3
RBEC-3
ABEC-5
RBEC-5
ABEC-7 ABEC-9 Radial bearings
(Except tapered roller bearings)
American Bearing Manufacturer's Association (ABMA) ANSI/ABMA Std.19.1 Class K Class N Class C Class B Class A Tapered roller bearings (Metric series)
ANSI/ABMA Std.19 Class 4 Class 2 Class 3 Class 0 Class 00 Tapered roller bearings (Inch series)

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