Inch Series Tapered Roller Bearings

**Introduction to NSK’s Inch Series Tapered Roller Bearings: Precision, Durability, and Performance**

In industrial machinery, automotive systems, and precision equipment, the reliability of rotating components is critical to operational efficiency and longevity. NSK’s **Inch Series Tapered Roller Bearings** are engineered to meet these demands, delivering exceptional load capacity, precision alignment, and durability in challenging environments. As part of NSK’s broader portfolio of precision motion and control technologies, these bearings combine advanced materials, optimized geometry, and rigorous manufacturing standards to ensure superior performance in high-stress applications.

### **Technical Features and Design Advantages**
NSK’s Inch Series Tapered Roller Bearings are designed with a conical raceway and tapered rollers, enabling them to handle **combined radial and axial loads** efficiently. The inch-based sizing ensures compatibility with legacy machinery and North American industrial standards, making them ideal for retrofitting or upgrading existing systems. Key features include:

– **Optimized Contact Geometry**: The precision-ground rollers and raceways distribute loads evenly, reducing stress concentrations and minimizing wear.
– **High-Strength Materials**: Manufactured from premium-grade steel and subjected to advanced heat treatment processes, these bearings resist fatigue and extend service life.
– **Advanced Cage Designs**: Options include pressed steel or machined brass cages, which enhance lubrication retention and reduce friction at high speeds.
– **Sealing and Lubrication Options**: Configurations with integrated seals or specialized grease fillings cater to contaminated or high-temperature environments.

### **Performance Benefits**
The Inch Series Tapered Roller Bearings excel in applications requiring **high rigidity, shock resistance, and precise rotational control**. Their tapered design inherently accommodates misalignment, reducing edge loading and premature failure. Additional advantages include:

– **Extended Maintenance Intervals**: Robust construction and efficient lubrication systems lower downtime.
– **Energy Efficiency**: Reduced friction losses contribute to lower power consumption in industrial drives and automotive transmissions.
– **Customization**: NSK offers tailored solutions for specific load, speed, or environmental conditions.

### **Typical Applications**
These bearings are widely used in sectors where precision and reliability are non-negotiable:

– **Industrial Machinery**: Conveyors, gearboxes, and heavy-duty pumps in mining, agriculture, and construction.
– **Automotive Systems**: Wheel hubs, differential assemblies, and transmission components in trucks and off-highway vehicles.
– **Precision Equipment**: Machine tool spindles and robotics, where smooth motion and load stability are critical.

By leveraging NSK’s expertise in precision engineering, the Inch Series Tapered Roller Bearings provide a dependable solution for demanding motion control challenges—enhancing performance while reducing total cost of ownership. Whether in harsh industrial settings or high-speed automotive applications, NSK’s innovations ensure optimal functionality and longevity.

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Designations Nominal Dimensions Basic Load Ratings
d
mm
D
mm
T
mm
B
mm
C
mm
Cone r (min.)
mm
Cup r (min.)
mm
Cr
N
C0r
N
25878/25820
34.925
73.025
23.812
24.608
19.05
3.5
2.3
87500
86000
HM89446A/HM89411
34.925
76.2
29.37
28.575
23.02
0.8
0.8
96500
106000
HM89446/HM89411
34.925
76.2
29.37
28.575
23.02
3.5
0.8
96500
106000
HM89446/HM89410
34.925
76.2
29.37
28.575
23.02
3.5
3.3
96500
106000
31594/31520
34.925
76.2
29.37
28.575
23.812
1.5
3.3
99000
96500
3478/3420
34.925
79.375
29.37
29.771
23.812
3.5
3.3
108000
106000
19138/19268
34.976
68.262
15.875
16.52
11.908
1.5
1.5
55500
53500
14139/14283
34.976
72.085
22.385
19.583
18.415
1.3
2.3
58000
56000
28138/28315
34.976
80
21.006
20.94
15.875
1.5
1.5
69500
64500
L68149/L68110
35
59.131
15.875
16.764
11.938
SPEC
1.3
43000
47000
L68149/L68111
35
59.975
15.875
16.764
11.938
SPEC
1.3
43000
47000
LM78349/LM78310
35
62
16.7
17
13.6
SPEC
1
47000
50000
LM78349/LM78310A
35
62
16.7
17
13.6
SPEC
1.5
47000
50000
M38547/M38511
35
65.987
20.638
20.638
16.67
3.5
2.3
65500
62500
23691/23621
35
73.025
26.988
26.975
22.225
3.5
0.8
92500
88500
HM88648/HM88610
35.717
72.233
25.4
25.4
19.842
3.5
2.3
78000
83500
25880/25821
36.487
73.025
23.812
24.608
19.05
1.5
0.8
87500
86000
HM89449/HM89410
36.512
76.2
29.37
28.575
23.02
3.5
3.3
96500
106000
3479/3420
36.512
79.375
29.37
29.771
23.812
0.8
3.3
108000
106000
44143/44348
36.512
88.501
25.4
23.698
17.462
2.3
1.5
89500
81000
46143/46368
36.512
93.662
31.75
31.75
26.195
1.5
3.3
129000
133000
JL69349/JL69310
38
63
17
17
13.5
SPEC
1.3
46000
49500
13889/13830
38.1
63.5
12.7
11.908
9.525
1.5
0.8
29700
30500
LM29749/LM29710
38.1
65.088
18.034
18.288
13.97
2.3
1.3
52000
55000