MRC7112KRDTPrecision Angular Contact Ball Bearing Set – Straight Bore, 60 mm ID, 95 mm OD, 18 mm Section Width, Open, 15° Contact Angle, Duplex Tandem, 2 Pieces

Product Description

What this part is

MRC 7112KRDT precision angular contact ball bearing set. Bore: 60 mm. Outside diameter: 95 mm. Section width: 18 mm per bearing. Series: 7100K, MRC’s extra-light angular contact section. Contact Angle: 15°. Precision Class: ABEC 7 (P4). Chrome steel balls run on an outer-ring-guided phenolic cage, rings open on both faces.

Decoding the designation

Series: 7100K, angular contact, extra light. Bore code 12: 60 mm. Type R: 15° contact angle with a counterbored outer ring. DT: matched tandem pair. Precision Class: ABEC 7, equivalent to P4. Searchable forms of the number include 7112KRDT, 7112 KR DT, 7112-KR-DT and 7112KR.

What these specs mean in practice

A tandem set puts both contact lines in the same direction, so thrust in that direction is shared across two ball complements. That roughly doubles one-way thrust capacity and axial stiffness over a single bearing in the same bore. A 15° contact angle favours speed and radial rigidity over thrust, and the counterbored outer ring gives each bearing a single high shoulder. ABEC 7 tolerances hold bore, outside diameter and raceway runout to super-precision limits, which is what keeps a spindle running true at speed. Dynamic Load Rating: 49.4 kN. Static Load Rating: 54 kN — static above dynamic is normal on an extra-light section, where the ball complement is limited by the section depth rather than by raceway strength.

Quantity and configuration

Unit Quantity: 2 Pcs, one matched tandem set. Total set width: 36 mm. The two bearings are ground together as a pair and belong to each other. Preload comes from the matched grinding, so the set is supplied at Light Preload rather than to a clearance class.

Fitting notes

Bore Type: straight, 60 mm. Housing bore: 95 mm. Both bearings mount facing the same way, inner rings clamped together against a square shaft shoulder and outer rings against a square housing shoulder. A tandem set is paired with an opposed bearing elsewhere in the arrangement, which sets shaft position and carries return thrust. Lubricant: oil. Operating range: −30 °C to 120 °C, the phenolic cage setting the upper figure.

Interchange guidance

ISO base number: 7012. Same-envelope 15° super-precision equivalents are SKF 7112 CD/P4A and NSK 7112CTRP4. The same envelope in a back-to-back or face-to-face execution (DB, DF) is a related size, since the ground offset and load path differ from a tandem set. A 29° or 40° bearing on this envelope is likewise a related size.

Origin

Country of origin: Italy.