SKF71911CDP4ADGASuper-Precision Angular Contact Ball Bearing, 55x80x13 mm, 15° Contact Angle, Light Preload, Universally Matchable, P4A

Product Description

What this part is

A single-row super-precision angular contact ball bearing in the metric 719 dimension series, 55 mm bore by 80 mm outside diameter by 13 mm wide. It is a spindle-class bearing: thin section, high running accuracy, and ground so that any two bearings of the same designation can be set face-to-face or back-to-back without shimming.

Decoding the designation

7 — angular contact ball bearing
19 — extra-thin 719 dimension series
11 — bore code, 55 mm
CD — 15° contact angle, super-precision internal design
GA — universally matchable, light preload when mounted as a pair or set
P4A — SKF super-precision class: P4 dimensional tolerance with P4A running accuracy

Correcting the source data

The previous copy claimed manufacture in Italy in one place and described the bearing as suitable for automotive use. Neither is supportable: no origin marking is documented for this item, so no country of origin is claimed here. A 15° super-precision spindle bearing is also not an automotive part — that description sends the wrong buyers to the page.

What these specs mean in practice

The 15° contact angle is the high-speed, low-friction end of the angular contact range. It gives excellent radial rigidity and lower heat generation than a 25° or 30° bearing, at the cost of axial load capacity and axial stiffness. Light preload (GA) is the choice when speed and thermal stability matter more than absolute rigidity — typical of grinding and high-rpm milling spindles. Mixing preload classes in one spindle stack defeats the whole arrangement, so match GA to GA.

Published ratings and mounting data

SKF does not publish basic dynamic and static load ratings for this designation in a source we could verify independently, so no rating figures are stated here rather than borrowing them from a similar 71911 variant. Boundary dimensions 55 x 80 x 13 mm are the ISO 719-series values and are confirmed.

Quantity and configuration

Supplied as a single bearing. Because the designation is universally matchable, it can be combined with another identical bearing to form a light-preload DF, DB or DT set — but only one bearing is included at this quantity.

Interchange guidance

Same-envelope equivalents in other makers’ super-precision ranges include NSK 7911CTYNSULP4 and NTN 7911CGD2GLP4 (both 15°, light preload, universally ground). Fafnir/Timken world numbering for this envelope is in the 2MM9911WI family. Confirm contact angle and preload letter before substituting: a 25° bearing in the same envelope will fit and will change the spindle’s stiffness and speed limit.