NTN Ultra-Thin Section Ball Bearings

The NTN ultra-thin section type ball bearings are bearings with an extremely thin design. There are three ultra-thin ball bearing types: radial, 4-point contact, and angular. Bearing seals are available for all types.

Each bearing type has different characteristics to best support a wide range of applications.

Types and features

1, Radial type ultra-thin section ball bearings

A deep groove is present in both the inner and outer rings of the NTN bearing, allowing them to support radial and axial loads in either direction as well as the complex loads which result from the combination of these forces. Deep groove ball bearings are used in the most applications.

2, 4-point contact type ultra-thin section ball bearings

When inner and outer rings are loaded in the radial direction, the ball comes into contact with the inner and outer rings at four points. The bearings are generally suitable for two contact points under a simple axial load or a complex load with a large axial load.

3, Angular type ultra-thin section ball bearings

Angular contact ball bearings have a straight line that runs through the point where each ball contacts the inner and outer rings at two points at 30° with respect to the radial direction. The bearings can receive a unidirectional axial load or a complex load of radial load and axial load. The ability to include an increased number of balls increases the load capacity of the bearing.
These NTN bearings are normally used in pairs for applications where it is necessary to control the axial movement via axial internal clearance or preload.

Part Number designation

The designation of NTN ultra-thin section ball bearings are as follow.

Dimension series code

Bearing cross section dimension (mm)

S: 4.762 x 4.762
A: 6.35 x 6.35
B: 7.938 x 7.938
c: 9.525 x 9.525
D: 12.7 x 12.7
F: 19.05 x 19.05
G: 25.4 x 25.4
H: 9.525 x 11.1
J: 9.525 x 12.7

Accuracy and radial internal clearance

Accuracy and radial internal clearance of radial type ball bearings

Accuracy and radial internal clearance of radial type ball bearings (Unit: um)
Bearing bore diameter No.	Tolerance and tolerance values					Radial internal clearance
	Mean bore diameter deviation Δ dmp	Mean outside diameter deviation Δ Dmp	Dimensional tolerance of inner ring and outer ring widths Δ Bs Δ Cs	Radial runout (Max.) Axial runout
	Mean bore diameter deviation Δ dmp	Mean outside diameter deviation Δ Dmp		Inner ring Kia Sia	Outer ring Kea Sea
010	0 -10	0 -13	0 -125	13	20	25-41
015	0 -13			15	20	30-46
020	0 -15			20	25	30-61
030							0 -15
035		0 -20						25	30	41-71
042	0 -20			36					30
047					0 -25	30	51-86
050									0 -25
055	41
070		0 -30
075				0 -30				41		46	61-107
100												0 -36	0 -36	46	51	71-122
140									0 -41								0 -41	0 -250	81-132
160	0 -46	0 -46		91-142
180	0 -46	0 -46		91-142	51
200	0 -51	0 -51		102-152
250	0 -76	0 -76		152-203
350	0 -76	0 -76		152-203		0 -102	0 -102	203-254

Accuracy and radial internal clearance of 4-point contact type/angular type ball bearings

Accuracy and radial internal clearance of 4-point contact type/angular type ball bearings (Unit: um)
Bearing bore diameter No.	Tolerance and tolerance values					Radial internal clearance (4-point contact type)
	Mean bore diameter deviation Δ dmp	Mean outside diameter deviation Δ Dmp	Dimensional tolerance of inner ring and outer ring widths Δ Bs Δ Cs	Radial runout (Max.) Axial runout
	Mean bore diameter deviation Δ dmp	Mean outside diameter deviation Δ Dmp		Inner ring Kia Sia	Outer ring Kea Sea
025
040
045
055
060
065
080
090
110
120
180
250
300
400
010	0 -10	0 -13	0 -125	7.5	10	25-38
015	0 -13			10	10	30-43
020	0 -15			13	13	30-56
030				13	13		0 -15	15	15
035		0 -20		41-66
042	0 -20				20	20
047							0 -25	51-76
050									0 -25
055	25	25
070				0 -30
075					0 -30	30				30	61-86
100												0 -36	0 -36	36	36	71-97
140									0 -250
160	0 -41	0 -41		41	41	81-107
200	0 -41	0 -41		41	41	81-107	0 -46	0 -46		46	46						91-117
350	0 -51	0 -51		51	51	102-127

Dimensional tolerance of shaft and housing bores

The table shows the recommended tolerance of shaft and housing bores when using NTN ultra-thin section type ball bearings.

Dimensional tolerance of shafts and housings (Unit: um)
Bearing bore diameter No.	For radial type ball bearings				For 4-point contact type/ angular type ball bearings
	Inner ring rotation		Outer ring rotation		Inner ring rotation		Outer ring rotation
	Shaft	Housing	Shaft	Housing	Shaft	Housing	Shaft	Housing
025
040
045
050
055
060
065
080
090
110
120
180
300
400
010	+10 0	+13 0	-10 -20	-13 -25	+10 0	+13 0	-10 -20	-13 -25
015	+13 0	+13 0	-13 -25	-13 -25	+13 0		-13 -25
020	+15 0	+15 0	-15 -30	-15 -30	+15 0		-15 -30
030									+15 0	-15 -30
035						+20 0		-20 -40			+20 0	-20 -40
042	+20 0		-20 -40		+20 0		-20 -40
047									+25 0	-25 -50			+25 0	-25 -50
055		+25 0		-25 -50											+25 0	-25 -50
070						+30 0		-30 -60			+30 0	-30 -60
075	+30 0		-30 -60		+30 0		-30 -60
100																	+35 0	+35 0	-35 -70	-35 -70	+35 0	+35 0	-35 -70	-35 -70
140		+40 0		+40 0											-40 -80	-40 -80
160	+45 0	+45 0	-45 -90	-45 -90	+40 0	+40 0	-40 -80	-40 -80
200	+45 0	+45 0	-45 -90	-45 -90	+40 0	+40 0	-40 -80	-40 -80	+50 0	+50 0	-50 -100	-50 -100	+45 0	+45 0	-45 -90	-45 -90
250	+75 0	+75 0	-75 -150	-75 -150
350	+75 0	+75 0	-75 -150	-75 -150	+100 0	+100 0	-100 -200	-100 -200	+100 0	+100 0	-50 -100	-50 -100

Installation-related dimensions of shafts and housings

The table shows the installation-related dimensions of shafts and housings when using NTN ultra-thin section type ball bearings.

Installation-related dimensions of shafts and housings (unit: mm)
Dimension series code	d_a d + f (Max.) d + e (Min.)		D_a d + h (Max.) d + g (Min.)		r_as (max.)
Dimension series code	e	f	g	h	r_as (max.)
S	3.4	5.3	4.2	6.1	0.2
A	4.6	7.3	5.4	8.2	0.4
B	5.7	9.3	6.6	10.2	0.8
C	6.9	11.3	7.7	12.2	0.8
D	9.2	15.3	10.1	16.2	1.3
F	13.9	23.3	14.8	24.2	1.8
G	18.7	31.3	19.5	32.1	1.8
J, H	6.9	11.3	7.7	12.2	0.2

NTN Category