Manufactured by CHG Bearing, the 71904 ACD/P4A is a precision Super-precision Angular Contact Ball Bearings. Key dimensional parameters include a 20 mm bore diameter, a 37 mm outer diameter, and a 9 mm overall width. This component is designed to meet standard load requirements and ensure consistent operational performance. For comprehensive technical evaluation, please explore the detailed specifications, dimensional data, product images, and CAD drawings provided below. A complete PDF data sheet is also readily available for direct download to support your engineering and procurement needs.

71904 ACD/P4A - Super-precision Angular Contact Ball Bearings
Technical Specifications
| Overview | |
|---|---|
| Part Number | 71904 ACD/P4A |
| Brand | CHG® |
| Characteristics | |
| Bearing Type | Super-precision Angular Contact Ball Bearing |
| Number of Rows | 1 |
| Contact Type | Normal Contact (Two-point Contact) |
| Ring Type | Integral Inner and Outer Rings |
| Design | High-capacity D Design |
| Universally Matchable | No |
| Axial Clearance / Preload | Not Applicable |
| Tolerance Class | P4A |
| Bearing Material | Bearing Steel |
| Sealing | Open |
| Dimensions | |
| Bore Diameter (d) | 20 mm |
| Width (B) | 9 mm |
| Outer Diameter (D) | 37 mm |
| Contact Angle α (°) | 25 ° |
| Performance | |
| Basic Dynamic Load Rating C (kN) | 5.72 kN |
| Basic Static Load Rating C₀ (kN) | 3.05 kN |
| Limiting Speed – Grease (r/min) | 40000 r/min |
| Limiting Speed – Oil-air (r/min) | 60000 r/min |
| Material | |
| Weight (kg) | 0.036 kg |
71904 ACD/P4A 37 mm 20 mm 9 mm Frequently Asked Questions about 71904 ACD/P4A Super-precision Angular Contact Ball Bearings
Find key technical answers regarding dimensions, specifications, and replacement options for this model.
To extend the trouble-free lifespan of CHG Bearing 71904 ACD/P4A, preventive maintenance routines should monitor operating housing temperature (normally maintaining below 70°C) and conduct regular vibration FFT analysis to identify early raceway micro-pitting before unexpected line halts occur.
The CHG Bearing 71904 ACD/P4A is rated for limiting speeds up to standard rated RPM under forced oil-mist or circulating oil lubrication regimes. When lubricated with factory-filled synthetic high-speed grease, safe continuous velocity is maintained at approximately 75% to 85% of the maximum nominal limit, preventing thermal runaway.
Each 71904 ACD/P4A produced in CHG Bearing manufacturing facilities features accurately profiled corner chamfers complying with DIN 5412 / ISO standard corner radii. When designing mating shafts and housing shoulders, machining an undercut or fillet radius strictly within the inner ring clearance limit (20 mm bore side) ensures perfect planar contact without edge binding.
Built for demanding industrial environments, the 71904 ACD/P4A Super-precision Angular Contact Ball Bearings by CHG Bearing boasts a dynamic load rating (Cr) of standard dynamic and a static load threshold (C0r) of standard static. The optimized internal raceway geometry balances stress distribution, mitigating edge loading even when operating under peak mechanical stresses.
