SKF7204ACDP4ADGASuper-Precision Angular Contact Ball Bearing, Matched Pair – Straight Bore, 20 mm ID, 47 mm OD, 14 mm Width, Open, 25° Contact Angle, Extra Light Preload

Product Description

What this part is

An SKF 7204 ACD/P4A DGA super-precision angular contact ball bearing set. Bore 20 mm, outside diameter 47 mm, width 14 mm per bearing, 28 mm across the pair. Open on both faces, one row of balls per bearing, phenolic cage. Supplied as a factory-matched pair of two bearings.

Decoding the designation

7204 is the ISO 72 medium dimension series on a 20 mm bore. ACD sets a 25° contact angle, where the plain CD form of the same envelope is 15°. P4A is SKF’s super-precision accuracy class, equivalent to ABEC 7. DGA marks a universally matchable set of two bearings, extra light preload; SKF writes the same bearing supplied singly as 7204 ACDGA/P4A.

What these specs mean in practice

The 25° contact angle trades speed for axial load capacity and axial stiffness against the 15° CD variant, which suits spindles where thrust dominates. Basic dynamic load rating is 16.6 kN and basic static load rating 8.0 kN per bearing, with a 34 000 r/min limiting speed. The fabric-base laminate phenolic cage is light and self-lubricating, which is what supports that speed.

Preload and clearance

Universally matchable rings are ground with offset faces, so clamping them together sets a defined extra light preload. Preload takes the place of running clearance, and a radial internal clearance class therefore does not apply.

Quantity and configuration

Two bearings, one matched set. Universal matching means the pair mounts back-to-back, face-to-face or in tandem, and further bearings of the same designation stack into the same arrangement.

Fitting notes

Shaft and housing seats are ground to suit the P4A ring tolerances, and rings are clamped axially against ground abutment faces. Oil or grease both apply, with oil the reference for the published speed figure.

Interchange guidance

FAG B7204-E-T-P4S-DUL, NSK 7204A5TYNDULP4 and Fafnir 3MM204WI-DUL are the equivalent 25° light-preload universally matchable pairs from the other super-precision makers. SKF 7204 CD/P4ADGA shares the envelope on a 15° contact angle, making it a related size rather than a substitution.