KF042AR0 bearings ( 4.25 inch x 5.75 inch x 0.75 inch) have the advantages of Extremely compact, lightweight design, composite load-bearing capacity, high rigidity, and flexible installation, and are therefore widely used in the Robot joints, aerospace, semiconductor equipment, medical instruments and optoelectronic turntables.

| Part Number | KF042AR0 |
| Series | KF Series |
| Precision ABEC | Precision Class 1 per ABEC 1F |
| Thin section bearings type | Standard Open REALI-SLIM Inch Series Bearing |
| Ring | AISI 52100 steel |
| Reference From | Kaydon KF042AR0 |
| Manufacturer Part Code | KF042AR0 |
| Seal type | open |
| Rolling bearing type | Angular contact ball bearing (type A) |
| Coating | No |
| Cage | Solid brass |
| Lubricant | No |
| Unit of measurement | inch |
| Separator | R = One-piece, circular pocket, stamped brass or non-metallic composite cage |
| Contact type | 2-point contact |
| Races/Balls Material | K = AISI 52100 steel rings and balls, no seals (open) |
| Weight [lb] | 2.04 |
| Contact angle - α [°] | 30 |
| Balls | Circular pocket separator 3/8" balls |
| Temperature - T(min) [°C] | -30 |
| Temperature - T(max) [°C] | +110 |
| Shaft diameter [inch] | 4.25 |
| F chamfer [inch] | 0.080 |
| H Radial cross section [inch] | 0.75 |
| Radial Thickness x Width ["] | F = 0.750 x 0.750 |
| d φ Inside [inch] | 4.25 |
| D Φ Outside [inch] | 5.75 |
| B Width [inch] | 0.75 |
| L1 Land Dia. [inch] | 4.805 |
| L2 Land Dia. [inch] | 5.195 |
| L3 Land Dia. [inch] | 5.365 |
| Cr Dynamic Radial [lbf] | 3785 |
| C0r Static Radial [lbf] | 6564 |
| Ca Dynamic Axial [lbf] | 8612 |
| C0a Static Axial [lbf] | 19036 |
The KF042AR0 Thin-section angular contact ball bearings mainly consist of a thin-walled inner ring, a thin-walled outer ring, steel balls, and a cage. Their cross-sectional dimensions are constant and extremely thin, with contact angles typically of 15°, 25°, or 30°, making them suitable for space-constrained installations.
Thin-section angular contact ball bearings utilize a thin-walled, constant cross-section design, resulting in lightweight construction and a small footprint, effectively reducing the overall weight of equipment. They can simultaneously withstand radial and axial loads, possessing high rigidity, high-speed capability, and good positioning accuracy, and are easy to install.















