SKFS7013ACDGBP4ASuper-Precision Angular Contact Ball Bearing Matched Pair 65 x 100 x 18 mm, 25° Contact Angle, Medium Preload, ABEC 7, Back-to-Back, 36 mm Total Width

Product Description

What this part is

A matched pair of single-row super-precision angular contact ball bearings in the 70-series, 65 mm bore, 100 mm outside diameter, 18 mm width per bearing. The rings are ground as a set for back-to-back mounting at a defined medium preload.

Decoding the designation

7013 — single-row angular contact ball bearing, 65 mm bore, 70 dimension series
AC — 25° contact angle in the SKF scheme
CD — super-precision execution
DGB — matched pair, back-to-back, medium preload
P4A — ABEC 7 precision class, SKF super-precision tolerance

What these specs mean in practice

A 25° contact angle carries substantially more thrust and gives higher axial stiffness than a 15° execution of the same 65 x 100 x 18 mm envelope, in exchange for a lower speed ceiling. Medium preload sits between the light setting used for maximum speed and the heavy setting used for maximum rigidity, and is the common choice for milling and turning spindles that see interrupted cutting loads. Back-to-back mounting spreads the load lines outward, which resists moment loads and holds the shaft square under overhung tooling. ABEC 7 running accuracy holds the radial and axial runout that spindle work depends on.

Quantity and configuration

2 Pcs, one matched pair. Total mounted width of the pair is 36 mm.

Fitting notes

The pair mounts in its ground orientation with the etched face markings aligned so the two outer rings meet at their narrow faces. Both rings are clamped fully home, so the preload comes off the ground faces rather than off clamp force, and rings are pressed by the ring being fitted rather than through the balls or cage.

Interchange guidance

Same-spec equivalents are 25° ABEC 7 medium-preload back-to-back 7013-size pairs under other schemes, such as an NSK 7013A5TRDUM or a Fafnir 3MM9113WI DUM. SKF 7013 CDGB/P4A at 15°, 7013 ACDGA/P4A at light preload, and single universally ground 7013 ACDGA/HCP4A executions are related sizes rather than interchanges.