MRCAngular Contact Ball Bearing Set – 45 mm ID, 85 mm OD, 19 mm Width, Straight Bore, Open, 40 Degree, ABEC 3, Tandem Pair Face-to-Face

Product Description

What this part is

MRC 7209PDTDF angular contact ball bearing set. Bearing type: Angular contact ball bearing. Bore: 45 mm. Outside Diameter: 85 mm. Overall Width: 19 mm per bearing. Contact Angle: 40°. Precision Class: ABEC 3 (P6). Bore Type: Straight. Closure Type: Open, both faces. Number Of Rows: 1 per bearing. Rolling Elements: Ball. Material: Chrome bearing steel. Series: MRC 7200 light, ISO 72 dimension series. Mounting Arrangement: Tandem pair mounted face-to-face (DT-DF).

Decoding the designation

72 — light section angular contact series, matching the ISO 72 dimension series.

09 — bore code giving Bore: 45 mm.

P — Contact Angle: 40°, the high-thrust MRC execution.

DT — matched tandem pair, ground so the two bearings share one direction of thrust equally.

DF — face-to-face, the tandem pair set against an opposing bearing so the assembly takes thrust both ways.

What these specs mean in practice

Contact Angle: 40°. The steep angle runs most of the load path along the shaft axis, giving this execution far more thrust capacity than a 15° or 29° bearing in the same envelope, at a lower speed ceiling. A tandem pair doubles that thrust capacity again in its own direction, and setting the pair face-to-face against an opposing bearing gives an assembly that is heavily loaded one way and located the other. Precision Class: ABEC 3. Bore, outside diameter and running accuracy are held tighter than a standard bearing, which keeps shaft location repeatable under the preload the ground faces set.

Quantity and configuration

Matched set, ground as a unit and supplied together. Open on both faces, straight bore. The bearings are installed in the orientation the grinding was made for.

Fitting notes

Straight bore on an interference-fit shaft seat, outer rings located in a bored housing. The set is clamped through all inner rings and all outer rings together so the ground offsets close and produce the intended preload. The ring faces are marked for orientation and the set is assembled to those marks.

Interchange guidance

The 45 x 85 x 19 mm envelope is the ISO 7209 seat and at a 40° contact angle corresponds to the 7209 B executions — SKF 7209 BE, FAG 7209-B and NSK 7209B. A 7209 AC at 25° or a 7209 C at 15° shares the same shaft and housing seats at a shallower angle and is a related size rather than an interchange.