RHP7221TDULP4-1/2PRSuper Precision Angular Contact Ball Bearing, Half Pair – 105 mm ID, 190 mm OD, 36 mm Width, P4, Light Preload, Open

Product Description

What this part is

RHP 7221TDULP4-1/2PR super precision angular contact ball bearing. Bore: 105 mm. Outside diameter: 190 mm. Width: 36 mm. Series: 72, ISO dimension series 02. Single row, open, straight bore, universally faced. Manufactured in the United Kingdom.

Decoding the designation

Cage: machined laminated phenolic resin, outer ring guided. Grouping: DU, paired unit. Preload: Light. Precision Grade: P4, equivalent to EP7, ABEC 7 and ISO Class 4. The -1/2PR suffix marks one half of a factory matched pair.

Specifications

Manufacturer: RHP (NSK Europe). Part Number: 7221TDULP4-1/2PR. Base Number: 7221. Bearing Type: super precision angular contact ball bearing, single row. Series: 72, ISO dimension series 02. Bore: 105 mm (4.1339 in). Outside Diameter: 190 mm (7.4803 in). Width: 36 mm (1.4173 in). Bore Type: straight. Number of Rows: 1. Rolling Elements: balls. Cage Type: machined, outer ring guided. Cage Material: laminated phenolic resin. Preload: light (DUL). Mounting Arrangement: universal, pairs back-to-back, face-to-face or in tandem with a matching 7221TDULP4. Internal Clearance: N/A. Closure Type: open. Precision Class: ISO Class 4. Precision Rating: P4 / EP7 / ABEC 7. Running Accuracy: inner ring radial runout Kia 5 µm maximum, outer ring radial runout Kea 10 µm maximum. Inner Ring Abutment Diameter (d1): 117 mm minimum. Outer Ring Abutment Diameters (D1, D2): 178 mm and 183 mm maximum. Fillet Radii (r, r1): 2.5 mm and 1.5 mm minimum. Lubrication Jet Pitch Circle Diameter: 137.4 mm. Internal Free Volume: 165.1 cm3. Recommended Shaft Fit: 3 µm mean interference. Locating Housing Fit: 7 µm mean clearance. Bearing Material: SAE 52100 through-hardened chrome bearing steel. Lubricant: oil/air or high-speed synthetic grease. Maximum Operating Temperature: 120 °C. Mass: 3.777 kg (8.33 lb). Design Units: metric. Harmonization Code: 8482.10.50. Country of Origin: United Kingdom.

What these specs mean in practice

P4 holds tighter running accuracy than a standard-grade bearing, which lowers runout and vibration in a spindle: inner ring radial runout 5 µm maximum, outer ring radial runout 10 µm maximum. The 72 section is the heavy choice at 105 mm bore, 190 mm outside diameter and 36 mm wide, and carries higher load ratings than the 70 section on the same shaft. Light preload gives the lowest internal friction and heat generation of the four preload classes and the highest permissible speed. Preload is set at manufacture, so no internal clearance value applies. The inner ring face carries a burnished spot and the outer ring outside diameter a V line, both marking the high point of radial runout; the V line also shows the direction of the contact angle.

Quantity and configuration

Unit Quantity: 1 Pc. One bearing, one half of a factory matched light-preload pair. Universal face control means the rings are pre-adjusted, so this piece pairs back-to-back, face-to-face or in tandem with another 7221TDULP4 at the marked light preload without ground spacers.

Interchange guidance

Carton designations: 7221TDULP4-1/2PR, 7221TDULP4, 7221-T-DUL-P4, 7221 T DUL P4, 7221TDUEP7, 7221B. In the 72 envelope at 105 mm bore the 15° executions are SKF 7221 CD/P4ADGA, FAG B7221-C-T-P4S-DUL, Fafnir 2MM221WI-DUL and NSK 7221CTRDULP4; the 25° executions are SKF 7221 ACD/P4ADGA, FAG B7221-E-T-P4S-DUL, Fafnir 3MM221WI-DUL and NSK 7221A5TRDULP4.