40TAC90CDDG bearings ( 40 mm x 90 mm x 20 mm) have the advantages of High axial stiffness and load-bearing capacity, 60° contact angle design, pre-installed and pre-loaded for easy installation, optional sealing for maintenance-free operation, and are therefore widely used in the Machine tool ball screws, machining centers, automated equipment, robots, precision measuring devices.

| Part Number | 40TAC90CDDG |
| Bearing Type | Angular Contact Super Precision Thrust Ball Bearings, TAC C Series Sealed type for Ball Screw Support (High-Rigidity) |
| Internal design | C = Contact angle 60 ° |
| Contact angle - α | 60 ° |
| Type | TAC |
| Preload | H = Heavy preload |
| Bearing Mass - m [lb] | 1.4859 |
| DB/DF Arrangement H preload [lbf] | 770 |
| DB/DF Arrangement H Axial Rigidity | 1107 N/µm |
| DB/DF Arrangement H Starting Torque | 0.29 N・m |
| DB/DF Arrangement H Measured Axial Clearance | -17 µm |
| Speed ratings (grease) - nB | 3468 min–1 |
| Dimension | |
| d φ Inside [inch] | 1.5748 |
| D Φ Outside [inch] | 3.5433 |
| B Width [inch] | 0.7874 |
| r min Chamfer [inch] | 0.0394 |
| r1 min Chamfer [inch] | 0.0236 |
| Dynamic Axial Capacity | |
| Ca 1 row [lbf] | 13867 |
| Ca 2 row [lbf] | 22656 |
| Ca 3 row [lbf] | 30027 |
| Abutment Dimensions | |
| Db max [inch] | 3.3465 |
| da min [inch] | 1.8504 |
| Da max [inch] | 3.3071 |
| db min [inch] | 1.8504 |
| Static Axial Capacity | |
| C0a 1 row [lbf] | 20010 |
| C0a 2 row [lbf] | 40174 |
| C0a 3 row [lbf] | 60407 |
| Other Arrangement | DB(<>), DF(><), DT(<<), DFD(><<), DBD(<<>), DFF(>><<), DBB(<<>>), DFT(><<<), DBT(<<<>) |
The 40TAC90CDDG Ball screw support bearings are typically composed of high-precision angular contact ball bearings paired back-to-back (DB) or in series (DT) configurations. They feature a small contact angle (15° or 20°) and high-rigidity cages (phenolic resin or brass) on both inner and outer rings, achieving a precision grade of P4 or higher. Some models integrate seals and lubrication holes, forming a preload unit.
Ball screw support bearings offer extremely high axial rigidity and load-bearing capacity, accurately withstanding bidirectional axial loads in screw drives. The back-to-back configuration provides anti-overturning moment capability, ensuring positioning accuracy. The preload design eliminates axial backlash, achieving backlash-free, low-friction operation with low heat generation, making them suitable for high-speed feed. They are factory-installed and ready to use, simplifying installation and adjustment.















