FafnirAAMM9111-2SMBRSpindle Deep Groove Ball Bearing – 55 mm ID x 90 mm OD x 18 mm, Open, Machined Bronze Cage, ABEC 7/9 P4S

Product Description

What this part is

Fafnir AAMM9111-2SMBR super-precision spindle deep groove ball bearing. Series: 9100. Base Number: MM9111. Bore Diameter: 55 mm. Outside Diameter: 90 mm. Overall Width: 18 mm. Bore Type: Straight. Closure Type: Open. Rolling Elements: Ball. Number Of Rows: 1. Bearing Material: Chrome steel. Design Units: Metric.

Decoding the designation

MM — the Fafnir super-precision spindle execution, Precision Class ABEC 7/9 / P4S.

9111 — the 9100 series, bore code 11, 55 mm bore, on the ISO 6011 envelope.

MBR — machined bronze cage.

What these specs mean in practice

Precision Class: ABEC 7/9 / P4S. Super-precision tolerances on bore, outside diameter and running accuracy, which is what lets a spindle hold position and run true at speed.

Cage Material: Machined bronze. Cage Type: Machined. A solid machined bronze cage is dimensionally stable, tolerates high temperature and marginal lubrication better than a polymer cage, and is specified where a spindle sees sustained high speed.

Rolling Elements: Ball. Number Of Rows: 1. This is a deep groove raceway, not an angular contact raceway, so it carries radial load with thrust in either direction rather than heavy one-way thrust.

Closure Type: Open. Lubricant: grease or oil. An open super-precision bearing takes whatever the spindle lubrication system supplies.

Bore Type: Straight. Bore Diameter: 55 mm. Outside Diameter: 90 mm. Overall Width: 18 mm.

Quantity and configuration

Unit Quantity: 1 Pc. Single bearing, supplied loose.

Interchange guidance

The cross-referenced parts are P4-class 6011 executions on the same 55 x 90 x 18 mm envelope. A commercial-grade 6011 shares the envelope but not the tolerance class or the bronze cage, so it is listed as a related size. Search also on the 305376-5 and EXP13001 carton numbers, which appear on the box for this part.