NTN7011CDBTGMP4Super Precision Angular Contact Ball Bearing Triplex Set – 55 mm Bore, 90 mm OD, 18 mm Width, 15 Degree Contact Angle

Product Description

What this part is

NTN 7011CDBTGMP4 super-precision angular contact ball bearing set. Series: 70. Bore: 55 mm. Outside diameter: 90 mm. Width per bearing: 18 mm. Total set width: 54 mm. Three bearings, factory matched and flush ground as a triplex set. Country of origin: Japan.

Decoding the designation

7011 — ISO 70 series, 55 mm bore. C — Contact Angle: 15°. DBT — a three-bearing stack: a back-to-back pair with a third bearing in tandem. GM — Preload: medium. P4 — Precision Class: ABEC 7. Searchable forms: 7011C DBT GM P4, 7011-C-DBT-GM-P4, 7011 C DBT GM P4. The carton also carries the Fafnir designation 2MM9111WICR TUM.

What these specs mean in practice

A 15° contact angle favours speed and radial stiffness over thrust capacity, which is what a machine-tool spindle needs. Dynamic Load Rating: 34.0 kN (7,650 lbf) per bearing. Static Load Rating: 28.6 kN (6,450 lbf) per bearing. Limiting Speed: 15,000 rpm on oil, 12,000 rpm on grease. Load centre: 18.5 mm. Operating temperature range: -40 to 120 °C.

Quantity and configuration

Three pieces, a complete factory triplex set. Total width across the set is 54 mm. Medium preload is established by factory flush grinding of the ring faces, so the three bearings clamp directly against one another.

Fitting notes

Shaft backing shoulder da min 62.0 mm. Housing shoulder Da max 83.0 mm, Db max 85.5 mm. Chamfer limits r 1.1 mm and r1 0.6 mm. Bore form: round cylindrical. In the DBT stack the tandem pair carries thrust in one direction and the opposing ring takes the reverse load.

Interchange guidance

Fafnir 2MM9111WICRTUM is the equivalent 15° triplex medium-preload set on the same 55 x 90 x 18 mm envelope. NTN 7011CDBTGLP4 is a related size — same envelope, light preload, different set rigidity.