Tips to Properly Grease a Bearing

Greasing bearings can make for a slippery situation...

In fact, it is estimated that 40-50% of bearing failures are the result of improper greasing/lubrication. Application and amount both need to be taken into account in order to ensure the proper performance and duty life of the bearing. Using the correct grease for the application will ensure proper/consistent lubrication while applying the manufacturers’ recommended quantity will ensure proper lubrication for the life of the bearing.

How do you know what grease is right for your bearing?

Many bearing manufacturers will recommend specific greases for your bearing, though sometimes the recommended grease may not be right for your application. Other problems can occur when exact bearing types are hard to identify and specify. Often, as in the case with Kyodo Yushi’s Multitemp LRL No. 3 and Kluber’s ISOFLEX NBU 15, each grease provides uses for similar functions although they are made of different materials and perform differently in different environments. Please see the table below to help identify the typical applications that two of the more common bearing greases cover. Prior to grease selection, the following parameters are usually analyzed or calculated: operating temperature, base oil viscosity, and speed.

Grease Type	Manufacturer	Base Oil	Thickness
Multemp LRL No. 3	Kyodo Yushi	Polyester	Viscosity 30 (40°C)
ISOFLEX NBU 15	Kluber	Mineral Oil, Ester Oil, & Synthetic Hydrocarbon	Viscosity 21 (40°C)

Recommended uses include ball screw bearings, spindles, linear guides, actuators, live tooling, or as an all-purpose bearing grease.

How do you know how much grease is right for your bearing?

A common and costly problem in grease application comes from over-greasing bearings. Over-greasing bearings can lead to abnormally high operating temperatures, damaged seals, and in some cases, such as electric motors, energy complications, and failure. Steer clear of this common problem by following proper and recommended grease amounts and by greasing on regularly scheduled preventative maintenance system (PMS). Under-greasing a bearing may also impact the life of your bearing. Applying lower than the recommended amount of grease may increase temperatures and metal contact, damaging the bearing through extreme wear. Spikes in noise levels and higher than normal temperature readings are good indications of having under-greased your bearing and could lead to bearing failure.

Here are some of the most common grease application amounts for Nachi TAB (ball screw support) bearings below:

Manufacturer	Bearing No.	Internal Space Volume (cc/each)	Fill Amount at 50% Full (cc/each)
Nachi	15TAB04	3.8	1.9
Nachi	17TAB04	3.8	1.9
Nachi	20TAB04	3.8	1.9
Nachi	25TAB06	4.8	2.4
Nachi	30TAB06	4.8	2.4
Nachi	35TAB07	5.8	2.9
Nachi	40TAB07	5.8	2.9
Nachi	40TAB09	14	7
Nachi	45TAB07	6.5	3.3
Nachi	45TAB10	15	7.5
Nachi	50TAB10	16	8
Nachi	55TAB10	16	8
Nachi	55TAB12	19	9.5
Nachi	60TAB12	19	9.5

Applying New Grease

Before applying new grease, be sure to review any manuals or specs as recommended by the bearing manufacturer. If there is existing grease on the bearing, be sure to thoroughly clean and remove all existing grease. New grease should be clean and should not contain any materials that would not be considered active to grease out of the tube, including dirt, dust, grime, or free particles. Grease should not be used if it appears tainted. Pack the bearings with an approved type and amount of bearing grease, reseal if necessary, and reapply into the application.

Be Wary of Using a Grease Gun or Your Fingers!

Applying grease with a common grease gun or your fingers isn’t always the easiest way of applying the right amount of grease at the right pressure. Too much pressure may force the grease past the seal, which should be avoided at all costs at the risk of blowing isolation seals, minimizing reliability of bearing enclosure, and/or reducing air circulation and causing circuitry issues. That’s why All World is offering easy-to-apply bearing syringes that apply only the required amount of grease where you want it, resulting in limited waste, limited mess, and a properly greased bearing.

View Grease Syringes