B71821-E-TPA-P4
Main technical Specifications
Detailed parameters and installation dimensions:
| Part Number | B71821-E-TPA-P4 |
| Design Type | B = Standard bearing, Lager balls, Steel balls |
| Series | B718..-E-TPA-P4 |
| Bearing Type | Super Precision Angular Contact Ball Bearing |
| Contact angle - α | (E) 25 ° |
| Dimension series | 718 (Ultra-light series) |
| Accuracy class | P4 |
| Seal | Open |
| Row No. | One |
| Bore Type | Z = Cylindrical bore |
| Units | Metric |
| Bearing Mass - m | 0.3 kg | 0.661 lb |
| Cage | TPA = Textile laminated phenolic resin, outer ring guided |
| Ball Material | GCr15SiMn |
| Ring Material | GCr15SiMn |
| Manufacturer Part Code | B71821ETPAP4 , B71821E-TPA-P4 |
| Reference From | FAG B71821-E-TPA-P4 |
| Dimension Inside - d φ (mm) | 105 |
| Dimension Outside - D Φ (mm) | 130 |
| Dimension Width - B (mm) | 13 |
| Dimension - rs(min.) | 1 mm | 0.039 inch |
| Dimension - rs1(min.) | 0.3 mm | 0.012 inch |
| Temperature - T(min) | -30°C |
| Temperature - T(max) | +100°C |
| Radial Dynamic Capacity - Cr | 21446 N | 4821 lbf |
| Radial static Capacity - C0r | 25397 N | 5709 lbf |
| Reference speed (grease) - nB | 7897 min–1 |
| Limiting speed (oil) - nG | 12886 min–1 |
| Mounting dimensions - da(h12) | 110 mm | 4.331 inch |
| Mounting dimensions - Da(H12) | 124.5 mm | 4.902 inch |
| Mounting dimensions - ra(max.) | 1 mm | 0.039 inch |
| Mounting dimensions - rb(max.) | 0.3 mm | 0.012 inch |
| Mounting dimensions - Etk(nom.) | 114.4 mm | 4.504 inch |
| Preload force - Fv L | 109 N | 24 lbf |
| Preload force - Fv M | 523 N | 117 lbf |
| Preload force - Fv H | 1190 N | 267 lbf |
| Axial rigidity - ca L | 139.8 N/μm |
| Axial rigidity - ca M | 251 N/μm |
| Axial rigidity - ca H | 349.8 N/μm |
| Lift-off force - KaE L | 317 N | 71 lbf |
| Lift-off force - KaE M | 1552 N | 348 lbf |
| Lift-off force - KaE H | 3667 N | 824 lbf |
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B71821-E-TPA-P4 refers to a type of B718..-E-TPA-P4 Super Precision Angular Contact Ball Bearing, with dimensions 105 mm (Bore) x 130 mm (OD) x 13 mm (Width), designed for High speed, ultra-precision, high rigidity, low operating friction, and long service life, primarily used in CNC machine tool spindles and other high-precision machinery, Its normal operating speed can reach: the grease speed ratings: 7897 rpm, oil speed ratings: 12886 rpm, featuring One (row) construction, TPA = Textile laminated phenolic resin, outer ring guided retainer to ensure extended service life, advanced Open, P4 (precision) for applications the field of precision machinery, especially high-speed and high-precision spindle systems, requiring high running accuracy and the accommodation of radial and axial loads simultaneously.. it's built to handle significant loads (dynamic radial: 21446 N, static radial: 25397 N, ), It weight approximately 0.3 kilogram.
- Min. Order: 1 Piece/(B71821-E-TPA-P4, 105 = ID, 130 = OD, 13 = B, 0.3 kg) or according to different suppliers
- Price: Different brands, different quality, different B71821-E-TPA-P4 prices, different suppliers and different quality determine different prices, you can ask the supplier in detail for the price according to your own needs.
- Precision Rating: DIN: P2~P0; ANSI: ABEC9~ABEC1; JIS: JIS~JIS0; ISO: CLASS2~NORMAL CLASS; GB/T30794 B~G
- Inquiry ways: The right of the inquiry form, Email, skype, Whatsapp
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What are the Benefits of choosing B71821-E-TPA-P4 bearings?
What are the applications of the B71821-E-TPA-P4 bearing?
How should choose the right model for a Precision spindle bearings?
Following the naming logic of "basic model + suffix," the key steps for selection are as follows:
Step 1: Contact Angle Determines Basic Load-Bearing Direction
Ultra-precision angular contact ball bearings have contact angles indicated by letters following their basic model number:
C = 15° Contact Angle: Suitable for ultra-high-speed rotation, relatively weak axial load-bearing capacity, a typical choice for high-precision, high-speed operation scenarios.
D (or AC) = 25° Contact Angle: General purpose, balancing high speed and axial rigidity.
E (or B) = 40° Contact Angle: Suitable for heavy-duty applications, good axial rigidity, but lower limiting speed.
Step 2: Design Variations Determine Performance Orientation
Ultra-precision spindle bearings have various internal design variations, identified by prefixes or suffixes:
No Code: Standard design, steel balls.
HC: Hybrid ceramic balls (silicon nitride balls + steel rings), enabling higher speeds, electrical insulation, lower heat generation, and longer lifespan.
X-life: Schaeffler's top-quality designation, representing higher load-bearing capacity, lower friction, and longer lifespan.
E: High-performance design, usually indicating superior performance. Internal Geometry
Step 3: Cage Code
Cage material directly affects high-speed performance and operational stability:
T: Laminated phenolic resin cage, outer ring guided (standard high-speed design)
TP: Also phenolic resin cage, but for rolling elements guided
P: Plastic cage (e.g., PEEK material)
G: Solid brass cage, suitable for higher temperatures or special operating conditions
Step 4: Universal Pairing and Preload
Ultra-precision bearings are all universally paired, allowing for arbitrary back-to-back, face-to-face, or tandem configurations. Preload is indicated by the following suffixes:
UL: Universal Light – Suitable for high-speed applications
UM: Universal Medium – Suitable for high-speed applications
UH: Universal Heavy – Suitable for high-rigidity applications
LO: Light Preload
L: Another way to indicate light preload
Step 5: Accuracy Grade
FAG ultra-precision bearing accuracy grade suffixes:
P4: ISO Class 4 accuracy, standard ultra-precision grade
P4S: Schaeffler standard, a higher accuracy grade than P4 (operating accuracy can reach P2 level), the standard configuration for FAG spindle bearings
P2: ISO Class 2 accuracy, the highest grade
Typical Model Interpretation
Using HC7008-E-T-P4S-UL For example:
HC: Hybrid ceramic ball bearing (ceramic ball + steel ring)
7008: 70 series, 40mm inner diameter
E: High-performance design (25° contact angle)
T: Phenolic resin cage, outer ring guided
P4S: Ultra-precision grade (higher than P4)
UL: Universal mating, light preload
This model designation indicates: a 70 series hybrid ceramic ball bearing with a 40mm inner diameter, 25° contact angle, phenolic resin cage, P4S precision grade, universal mating, and light preload—suitable for general applications such as high-speed machining center spindles.
Key Selection Points Summary
Determine Contact Angle: C (15° high speed), D/AC (25° general purpose), E/B (40° heavy load)
Select Material: No designation = steel balls, HC = ceramic balls (higher performance)
Match Cage: T (phenolic resin) suitable for most high-speed applications
Set Preload: UL (light preload) general purpose, UM/UH for high rigidity requirements
Confirm Accuracy: P4S is the standard configuration for FAG ultra-precision bearings
Following the order of "Contact Angle → Material → Cage → Preload → Accuracy" will provide a complete understanding of the FAG ultra-precision angular contact ball bearing models.
What is the mounting procedure for B71821-E-TPA-P4 bearings?
Cleaning and Inspection: Clean the bearing in a dust-free environment. After a rough wash to remove contaminants, perform a fine wash until the bearing feels smooth and responsive to the touch. Simultaneously check the accuracy of the mating surfaces of the shaft and bearing housing.
Measurement and Fitting: Precisely measure the bearing's inner and outer diameters. Mark the corresponding positions on the shaft and housing bores for alignment during assembly to compensate for any deviations.
Installation and Positioning: Apply pressure evenly using a specialized tool, focusing only on the interference fit rings. If heat fitting is used, tighten the inner ring during cooling to prevent clearance from affecting the preload.
Preload Adjustment: When installing in pairs, ensure the parallelism of the inner and outer spacers is ≤1μm. Adjust the preload force to the specified value by grinding the spacers.
Lubrication Inspection: Add the specified amount of grease or oil mist lubricant. After installation, manually rotate the bearing to check its flexibility and operating noise.
Special Note for mounting B71821-E-TPA-P4 bearings?
Clean Environment: Operation must be performed in a dust-free cleanroom with humidity ≤65% to prevent dust and impurities from affecting accuracy.
No Striking: Direct striking of the bearings is strictly prohibited. Special tools must be used, and force must be applied evenly.
Matching Marks: Bearings used in pairs are not interchangeable. Installation must strictly follow the factory matching marks.
Rust-Proof Storage: Long-term storage requires regular rust-proofing treatment. Maintain ventilation and avoid corrosive gases.