Inch Series Miniature Ball Bearings Catalog
BRK offers the following series of Inch Series Miniature Ball Bearings at premium quality and competitive price:
- R2 Series (Extra-Small Inch) – Very compact inch-series miniature bearings designed for light radial loads and high-speed precision devices.
- R3 Series (Small Inch) – Small-bore bearings offering balanced performance and versatility for instruments and small electric motors.
- R4 Series (Light Inch) – Slightly larger miniature bearings providing higher load capacity while retaining smooth, low-torque operation.
- R4A Series (Wide Inch) – Wider variant of R4 for increased load-carrying capability and rigidity in compact mechanical assemblies.
- R6 Series (Medium Inch) – Mid-size inch bearings combining good radial strength and durability for motors, tools, and conveyors.
- R8 Series (Heavy Inch) – Robust miniature bearings engineered for moderate-to-heavy loads at reliable speeds in industrial equipment.
- R10 Series (Large Inch) – Largest of the common inch miniature series, suited for heavier-duty applications with strong radial performance.
ABEC grades 1, 3, 5, 7, and 9 are available
Material - standard AISI 52100 chrome steel, 440C, 420, 304 or 316 stainless steel available upon request
FILTERS
| Product Number | Model | Type | Bore Dia. (d) (in) |
Outer Dia. (D) (in) |
Chamfer Dimension (r) (in) |
Width (B) (in) | Weight (g) | Limiting Speed (rpm) | Static Load Rating (Cor) (lbs) | Dynamic Load Rating (Cr) (lbs) |
|---|---|---|---|---|---|---|---|---|---|---|
| R2 | / | Open | 0.1250 | 0.3750 | 0.0120 | 0.1562 | 1.04 | 58000 | 50.40 | 144.00 |
| R2 | 2RS | Rubber Seals | 0.1250 | 0.3750 | 0.0120 | 0.1562 | 1.37 | 49000 | 50.40 | 144.00 |
| R2 | ZZ | Metal Shields | 0.1250 | 0.3750 | 0.0120 | 0.1562 | 1.37 | 49000 | 50.40 | 144.00 |
| R3 | / | Open | 0.1870 | 0.5000 | 0.0120 | 0.1562 | 2.21 | 48000 | 110.25 | 294.75 |
| R3 | 2RS | Rubber Seals | 0.1870 | 0.5000 | 0.0120 | 0.1960 | 2.95 | 41000 | 110.25 | 294.75 |
| R3 | ZZ | Metal Shields | 0.1870 | 0.5000 | 0.0120 | 0.1960 | 2.95 | 41000 | 110.25 | 294.75 |
| R4 | / | Open | 0.2500 | 0.6250 | 0.0120 | 0.1960 | 4.46 | 43000 | 138.38 | 333.00 |
| R4 | 2RS | Rubber Seals | 0.2500 | 0.6250 | 0.0120 | 0.1960 | 4.51 | 36000 | 138.38 | 333.00 |
| R4 | ZZ | Metal Shields | 0.2500 | 0.6250 | 0.0120 | 0.1960 | 4.51 | 36000 | 138.38 | 333.00 |
| R4A | / | Open | 0.2500 | 0.7500 | 0.0160 | 0.2188 | 7.48 | 40000 | 199.13 | 526.50 |
| R4A | 2RS | Rubber Seals | 0.2500 | 0.7500 | 0.0160 | 0.2812 | 10.00 | 34000 | 199.13 | 526.50 |
| R4A | ZZ | Metal Shields | 0.2500 | 0.7500 | 0.0160 | 0.2812 | 10.00 | 34000 | 199.13 | 526.50 |
| R6 | / | Open | 0.3750 | 0.8750 | 0.0160 | 0.2188 | 9.02 | 37000 | 317.00 | 735.15 |
| R6 | 2RS | Rubber Seals | 0.3750 | 0.8750 | 0.0160 | 0.2812 | 11.70 | 31000 | 317.00 | 735.15 |
| R6 | ZZ | Metal Shields | 0.3750 | 0.8750 | 0.0160 | 0.2812 | 11.70 | 31000 | 317.00 | 735.15 |
| R8 | / | Open | 0.5000 | 1.1250 | 0.0160 | 0.2500 | 18.00 | 30000 | 540.02 | 1150.17 |
| R8 | 2RS | Rubber Seals | 0.5000 | 1.1250 | 0.0160 | 0.3125 | 22.10 | 26000 | 540.02 | 1150.17 |
| R8 | ZZ | Metal Shields | 0.5000 | 1.1250 | 0.0160 | 0.3125 | 22.10 | 26000 | 540.02 | 1150.17 |
| R10 | / | Open | 0.6250 | 1.3750 | 0.0310 | 0.2812 | 33.50 | 24000 | 727.96 | 1340.15 |
| R10 | 2RS | Rubber Seals | 0.6250 | 1.3750 | 0.0310 | 0.3438 | 37.00 | 20000 | 727.96 | 1340.15 |
| R10 | ZZ | Metal Shields | 0.6250 | 1.3750 | 0.0310 | 0.3438 | 37.00 | 20000 | 727.96 | 1340.15 |
All information in this catalog has been thoroughly checked for accuracy. However, dimensions and specifications are subject to change without notice. Please contact BRK Bearings for the most current bearing catalog data.
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