Barden120HDMSuper-Precision Angular Contact Ball Bearing – Straight Bore, 100 mm ID, 150 mm OD, 24 mm Width, Open, 15° Contact Angle, Medium Preload, P4S.

Product Description

What this part is

Barden 120HDM super-precision angular contact ball bearing. Bore: 100 mm. Outside diameter: 150 mm. Width: 24 mm. Open, straight bore, chrome steel rings and balls.

Decoding the designation

120: Barden size code, 100 mm bore on the 150 mm outside diameter and 24 mm width envelope. H: 15° contact angle series. D: universally matchable duplex construction. M: medium duplexing preload, 1,375 N. 1/2PR: one piece, one half of a factory matched pair.

What these specs mean in practice

Basic dynamic load rating: 79.9 kN (17,960 lbf). Basic static load rating: 92.0 kN (20,690 lbf). On this light section the static rating sits above the dynamic rating, which is the normal relationship here. A 15° contact angle runs faster and takes less thrust than a 25° angle of the same envelope, which suits high-speed spindle positions. Limiting speed: 10,000 r/min on grease and 15,000 r/min on oil. Axial rigidity in the medium preload class: 181.4 N/µm.

Preload and matching

Medium duplexing preload: 1,375 N. Axial breakaway load: 4,624 N. Medium preload gives higher stiffness and tighter shaft location than light preload, at a higher running temperature. Universally matchable construction lets this bearing be combined directly with another 120HDM piece, with the preload arriving as ground.

Quantity and configuration

One bearing, one half of a factory matched duplex pair. Precision class P4S, which is ABEC 7 dimensional accuracy with ABEC 9 running accuracy.

Cage construction

One-piece phenolic halo cage. Phenolic runs quieter and lighter than brass at high speed and holds oil in the fabric, which suits sustained high-speed spindle duty.

Interchange guidance

The 120H envelope matches ISO 7020 at 100 x 150 x 24 mm. Same-envelope equivalents at 15° and medium preload: Fafnir 2MM9120WI-SUM, FAG B7020-C-T-P4S-UM, SKF 7020 CDGB/P4A, NSK 7020CTYSUMP4, RHP 7020CTSUMP4. Barden 2120H is a related size on the same envelope at a 25° contact angle. Searchable forms: 120HDM, 120 HDM, 120H-DM, 120HDM-1/2PR, 120H D M 7020.