Klüber to Mobil Spindle Grease Cross Reference: Approval and Speed

Start with the spindle specification

Check whether the assembly uses grease lubrication and whether field relubrication is permitted. Some spindle assemblies have a service procedure tied to their bearing arrangement and preload. Keep the assembly designation and manual revision with the lubricant enquiry so the supplier can identify the correct requirement.

Klüber describes ISOFLEX NBU 15 as a spindle-bearing grease containing ester, synthetic hydrocarbon and mineral oils with a barium complex thickener. That description identifies the product family and formulation; it does not authorize its use in every spindle.

Source: Klüber: ISOFLEX NBU 15.

Calculate the speed factor on a stated basis

Where the data sheet uses n × dₘ, n is rotational speed in r/min and dₘ is the mean bearing diameter in millimetres. The mean diameter is (d + D) / 2, using bearing bore d and outside diameter D. Keep that definition attached to the result; a value described only as “DN” may use a different diameter convention.

SKF speed-factor definition; the bearing-specific life charts in that document are not applied to spindle selection here: SKF: energy efficient deep groove ball bearings, speed-factor definition.

What the product descriptions can tell you

Swipe the table sideways to read every column.

Source: Klüber: ISOFLEX NBU 15; Klüber: ISOFLEX TOPAS NB 52; Mobil: Polyrex EM product data.

Keep the substitution and service instructions together

A workable approval should identify the replacement by full product name and specify how to deal with residual grease. It should also state the filling method and quantity, the running-in sequence, and the checks required before production resumes. Request those instructions from the assembly maker or the responsible spindle service provider.

Use the same measurement points and operating sequence for the before-and-after record. Note speed, elapsed running time, measured temperature and any vibration or noise observations required by the service procedure. Do not invent a universal temperature rise or vibration threshold; use the limits for that spindle.

Include these details in a spindle-grease enquiry

• Machine and spindle assembly designations, with the lubricant specification page.
• Bearing designations, bore and outside diameter where available, plus the operating speed range.
• Existing grease, service history and reason for the proposed change.
• Required pack size and quantity, and the party responsible for approving the substitution.

If the documentation names NBU 15 and the immediate need is a replenishment order, quote NBU 15 in full. Resolve any proposed alternative through the approval process before changing the maintenance instruction.