SKF71910ACDP4ADGAThin-Section Super-Precision Angular Contact Ball Bearing 50x72x12 mm 25° ABEC 7 Light Preload

Product Description

What this part is

An SKF 71910 ACD/P4A DGA thin-section super-precision single-row angular contact ball bearing, 50 mm bore by 72 mm outside diameter by 12 mm width. The 719 series is the slimmest of the standard angular contact sections, which is what allows a 50 mm spindle to sit inside a 72 mm housing bore. It is built for compact high-speed spindles, precision rotary axes, machine tool sub-spindles and ball screw support positions.

Decoding the designation

71910 — single-row angular contact ball bearing, 719 thin section, 50 x 72 x 12 mmAC — 25° contact angle in the SKF schemeD — super-precision spindle bearing designP4A — ABEC 7 super-precision classDGA — universally matchable, giving light preload when paired

What these specs mean in practice

The thin section is the reason this bearing exists. Only 11 mm of radial wall separates bore from outside diameter, so a designer can support a large-diameter and therefore stiff shaft inside a small housing. Shaft stiffness rises with the fourth power of diameter, so trading bearing section for shaft diameter is usually the better deal in a compact spindle.

A 25° contact angle carries substantially more thrust and offers more axial stiffness than a 15° bearing of the same envelope while still running fast, which suits a spindle that sees real axial cutting load.

Light preload keeps frictional heat low, which matters more in a thin-section bearing than in a heavy one: there is less steel to conduct heat away from the raceways. The phenolic cage works with that — light, self-lubricating, low cage friction — within its 120 °C ceiling, which places the bearing in oil-mist, oil-air or light-grease systems.

Universal matching means the ring faces are ground so any two bearings of this designation reach the tabulated light preload when clamped, in back-to-back, face-to-face or tandem arrangement, with no shimming.

Published ratings and mounting data

Bore: 50 mmOutside diameter: 72 mmWidth: 12 mmRows: 1Contact angle: 25°Dynamic load rating C: 12.7 kNStatic load rating C0: 9.8 kNPrecision class: ABEC 7 / ISO P4APreload: lightCage: phenolicOperating temperature range: –30 °C to +120 °CClosure: open

Quantity and configuration

This listing supplies one bearing. Building a matched pair or triplet requires additional bearings of the same designation. Spacer rings, lock nuts and housings are not included.

Fitting notes

The high shoulder on the outer ring marks the contact angle direction and sets the arrangement. Back-to-back carries moment load and is the usual spindle configuration; face-to-face tolerates slight misalignment; tandem doubles thrust capacity in one direction. Thin-section rings deflect readily, so an out-of-round housing bore transfers its error straight into the raceway: seats held to roundness and cylindricity limits matching the bearing class are what deliver true running. Mounting pressure goes on the ring faces, never through the balls.

Interchange guidance

Genuine equivalents are 71910-envelope super-precision bearings at 25° with light preload and P4 class, including NSK 7910A5TRSUL, FAG B71910E.T.P4S.UL, Fafnir 3MM9310WI-CR-SUL and RHP 7910X2TAUL. The 71910 CD/P4A at 15° shares the 50 x 72 x 12 mm envelope but is a different part, as are medium and heavy preload variants and anything at P0 or P5 class. 7910 in the title is the short form of the same 719-series envelope.