Thin Section Angular Contact Ball Bearings
Type A Thin-Section Bearings for Precision Combined LoadsBearing Type: Single-row thin-section angular contact ball bearing
Contact Angle: 30° standard Type A contact angle
Series: HK Prefix Models and HW Prefix Models
HK Prefix Models: Open: KAA, KA, KB, KC, KD, KF, KG; sealed: JHA, JA, JB, JU, JG
HW Prefix Models: A4, A6, A7, A8, A9, A10, A11, A12, A13, A16 and A24 structures
Bore Range: 0.625–20 in (15.875–508 mm).
Technical Specifications
| Specification | Details |
|---|---|
| Bearing Type | Single-row thin-section angular contact ball bearing |
| Contact Angle | 30° standard Type A contact angle |
| Series | HK Prefix Models and HW Prefix Models |
| HK Prefix Models | Open: KAA, KA, KB, KC, KD, KF, KG; sealed: JHA, JA, JB, JU, JG |
| HW Prefix Models | A4, A6, A7, A8, A9, A10, A11, A12, A13, A16 and A24 structures |
| Bore Range | 0.625–20 in (15.875–508 mm) |
| Loads | Combined radial and axial; standard Type A supports axial load in one direction |
| Precision | P0 and P4 precision classes |
| Steel Options | Vacuum-degassed GCr15 or W martensitic stainless steel (>58 HRC) |
| Temperature | -50°C to +100°C; material capability depends on rings, cage, seals and lubrication |
Thin Section Angular Contact Ball Bearings Overview
Type A thin-section angular contact ball bearings use radial clearance to establish a defined 30° contact angle. They combine high radial capacity with one-direction axial capacity while retaining a compact equal-section geometry.
The product range is organized into HK-prefix and HW-prefix models. HK-prefix models cover compact open and sealed series with standardized equal sections, while HW-prefix models provide A4–A24 section options for different load, stiffness and installation requirements.
Matched Mounting and Preload
A single Type A bearing carries axial load in one direction. Matched DB, DF or DT arrangements are used when bidirectional axial capacity, greater moment rigidity or higher one-direction thrust capacity is required.
- DB: high moment stiffness
- DF: improved tolerance of mounting misalignment
- DT: increased one-direction thrust capacity
- Clearance and preload can be adjusted with precision spacers or shims
Material Performance and Operating Limits
Vacuum-degassed GCr15 has balanced mechanical properties, supports high loads and can operate up to 150°C, but it is not intended for corrosive environments.
- W martensitic stainless steel: hardness above 58 HRC and excellent corrosion resistance
- W material receives one or more deep-freezing treatments and is suitable for -80°C to +150°C
- Final catalog rows list -50°C to +100°C; verify cage, seals and lubrication for extended-temperature service
HK-prefix open/sealed series and HW-prefix A4–A24 structures
Structure and Series
| Type | Configuration | Function |
|---|---|---|
| HK Prefix Models | Open and sealed series | Fixed-section lightweight design |
| HW Prefix Models | A4–A24 section families | Select by capacity and space |
Performance Characteristics
HK-prefix bearings include open and sealed structures, allowing the sealing arrangement to be selected according to contamination and lubrication conditions. HW-prefix bearings use A4–A24 section codes so designers can match bearing capacity, stiffness and installation space while retaining the lightweight benefits of thin-section construction.
Model Selection : Choose the prefix, section, precision and sealing configuration for the application.
Typical Applications
- Robot joints and precision rotary axes
- Optical and radar positioning systems
- Medical imaging equipment
- Semiconductor and inspection equipment
- Aerospace gimbals and actuators
- Precision indexing and rotary tables
Available Models & Specifications
Click on any part number to view detailed CAD drawings and download PDF specifications.
