SKF71905FEGAP4ASuper-Precision Angular Contact Ball Bearing – 25 mm ID, 42 mm OD, 9 mm Width, Open, Light Preload

Product Description

What this part is

SKF 71905 FEGA/P4A single-row super-precision angular contact ball bearing. Series: 719, extra-light section. Bore: 25 mm. Outside diameter: 42 mm. Width: 9 mm. Open on both faces. Country of origin: Italy. Searchable forms of the designation include 71905FEGAP4A, 71905-FEGA-P4A and 71905 FEGA P4A, with 7905 and 1905 used as short forms in the trade.

Decoding the order code

Precision Class: P4A — SKF’s super-precision class for machine tool spindle bearings, equivalent to ABEC 7. Preload: GA, light. Light preload holds the ball complement in defined contact with both raceways for accurate shaft location while keeping frictional heat low, which is what allows the higher speeds a spindle needs. The FEGA execution is recorded as an order-code variant on this listing.

What these specs mean in practice

A P4A bearing runs tighter running accuracy on both radial and axial runout than a standard-class bearing of the same envelope, so a spindle built on it holds tool position more closely and generates less vibration at the cut. The 719 extra-light section puts a 42 mm outside diameter on a 25 mm bore, which keeps spindle nose diameter and rotating mass down.

Quantity and configuration

One bearing. Universally matchable execution: a GA bearing can be arranged with further bearings of the same designation in back-to-back, face-to-face or tandem sets without shims or grinding, and the preload of the completed set follows from the GA class.

Fitting notes

Straight bore, mounted on a cylindrical shaft seat. Preloaded bearings are supplied without a running clearance, so Internal Clearance reads N/A on this part. Handling and mounting are performed with the marked faces of matched bearings aligned as arranged.

Interchange guidance

Base number: 71905. Same envelope in the Fafnir spindle range: 2MM9305WI, the Fafnir 9300 series mapping to the ISO 719 family. Executions of 71905 carrying a different design or preload code are a related size on the same 25 x 42 x 9 mm envelope rather than a direct substitution.