MRC7209DBMatched Angular Contact Ball Bearing Pair – 45 mm Bore x 85 mm OD x 19 mm Width, 29°, Back-to-Back, ABEC 5

Product Description

What this part is:

MRC 7209DB matched pair of single-row angular contact ball bearings, ground for back-to-back mounting. Bore: 45 mm. Outside Diameter: 85 mm. Overall Width: 19 mm per bearing. Total Width: 38 mm as a mounted pair. Contact Angle: 29°. Precision Class: ABEC 5. Number Of Rows: 1 per bearing. Rolling Elements: Balls. Bore Type: Straight. Closure Type: Open both faces. Material: Chrome steel. Unit Quantity: 2 Pcs.

Decoding the designation:

7200 — MRC’s angular contact light series. Contact Angle: 29° is the standard MRC angle for this series, and it is the middle of the angular contact range: more thrust capacity than a 15° execution, more speed headroom than a 40° one.

09 — the bore code. Multiplied by five it gives Bore: 45 mm.

DB — a matched pair mounted back-to-back. The two outer-ring faces meet at the centre and the load lines diverge outward, which spreads the effective support span well beyond the physical width of the pair.

What these specs mean in practice:

Precision Class: ABEC 5 tightens bore and outside diameter tolerance and, more importantly, radial and axial runout. That matters where shaft position is a specification rather than a consequence — a machine-tool spindle, a grinding head, a precision gearbox input. A back-to-back pair takes thrust in both directions and carries an overturning moment, because the diverging load lines give the set a wide virtual support base. The faces are ground so that clamping the pair sets the preload directly, with no shim stack measured at assembly. Contact Angle: 29°. Bore: 45 mm. Outside Diameter: 85 mm. Overall Width: 19 mm per bearing.

Quantity and configuration:

Unit Quantity: 2 Pcs. One factory-matched back-to-back pair, straight bore, open on all faces, supplied together as a ground set.

Fitting notes:

The two bearings are kept together and installed in the orientation their ground faces define, with the marked faces of the outer rings meeting. Both inner rings are clamped against each other and both outer rings against the housing, so the ground offset closes as the set is tightened and produces the designed preload. Mounting force is applied through the ring being fitted. A precision-class set expects ground and measured shaft and housing seats and clean handling.

Interchange guidance:

The direct match is another MRC 7209DB set at the same class. 45 x 85 x 19 mm is the 7209 envelope, so an angular contact bearing of that size will enter the same seat, but a substitution has to agree on the 29° contact angle, the ABEC 5 class and the back-to-back grind together. An angular contact 7209 at 15°, 25° or 40° is a related size, carrying different thrust capacity and stiffness on the same envelope.

Searchable variants:

7209DB, 7209-DB, 7209 DB, 7209D B, MRC 7209DB, MRC 7209 DB set.