Page 341 - needle bearings

Appendix
NTN

Ordinary tolerance for straightness Unit : mm Ordinary tolerance for straightness Unit : mm
Classification by plate thickness Classification by plate thickness
1.6 and less Over 1.6 3 incl. Over 3 6 incl. 3 and less Over 3 6 incl. Over 6 12 incl.
Tolerance class Tolerance class
Cutting width division Class-A Class-B Class-A Class-B Class-A Class-B Cutting width division Class-A Class-B Class-A Class-B Class-A Class-B
120 and less 0.2 0.3 0.2 0.3 0.5 0.8 120 and less 0.3 0.5 0.5 1.0 ʵ 1.6
Over 120 - 315 incl. 0.3 0.5 0.3 0.6 1.0 1.6 Over 120 - 315 incl. 0.6 1.2 0.8 1.6 ʵ 2.0
Over 315 - 1000 incl. 0.4 0.9 0.5 1.0 1.4 2.0 Over 315 - 1000 incl. 1.6 3.0 2.0 3.0 ʵ 3.0
Over 1000 - 2000 incl. 0.6 1.2 0.8 1.6 2.5 3.0 Over 1000 - 2000 incl. 3.0 6.0 4.0 6.0 ʵ 6.0
Over 2000 - 3150 incl. 0.9 1.6 1.0 2.2 2.8 4.5 Over 2000 - 3150 incl. 4.5 9.0 5.5 9.0 ʵ 9.0
Remarks: Non-applicable to cutting width of less than 20 times as much as
plate thickness or cutting width of less than 30mm.

Ordinary tolerance for sintered metal parts Ordinary tolerance for width Unit : mm
JIS B 0411 class Fine class Medium class Coarse class
Dimensional division
This Standard specifies the ordinary tolerance which is
6 and less ʶ0.05 ʶ0.1 ʶ0.2
applied to the machining dimensions of sintered
mechanical parts and sintered oil-contained bearing, of Over 6 - 30 incl. ʶ0.1 ʶ0.2 ʶ0.5
sintered metal parts, but excluding machining methods Over 30 - 120 incl. ʶ0.15 ʶ0.3 ʶ0.8
other (e.g. cutting, etc.) than the machining method
Over 120 - 315 incl. ʶ0.2 ʶ0.5 ʶ1.2
specific for sintered metal parts.
Ordinary tolerance is applied to the dimensions for
which special accuracy is not required functionally and, Ordinary tolerance for height Unit : mm
therefore, applicable tolerances are indicated in batch, class Fine class Medium class Coarse class
without individual indication of them, in relevant Dimensional division
specification, drawings, etc. 6 and less ʶ0.1 ʶ0.2 ʶ0.6
Ordinary tolerance shall be indicated by either one of Over 6 - 30 incl. ʶ0.2 ʶ0.5 ʶ1
the following methods (1) and (2).
Over 30 - 120 incl. ʶ0.3 ʶ0.8 ʶ1.8
(1) Numerical value table for each dimensional division
(2) Applicable Standard No. and tolerance class
Ex. JIS B0411, Fine Class
Definition of terms: The terms used in this Standard are
as defined below.
(1) Width: Perpendicular dimension against
compressing direction in compressive molding of
powders, as illustrated in Fig. a.
(2) Height: Dimension parallel to compressing direction
in molding of powders, as illustrated in Fig. b.

Compressing Compressing
direction direction

Пa1
b
Пa2
a1
b1
a2 b2
a3
Пa3

Class: The ordinary tolerance class shall be three classes of “Fine
Class”, “Medium Class” and “Coarse class”.
Reference: The numerical values every each class of “Fine Class”,
“Medium Class” and “Coarse class” match “Fine Series,
Medium Series and Coarse Series specified in ISO 2768
(Permissible machining variations in dimensions without
tolerance indication)

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