Radial Ball Bearings Radial Ball Bearings - Rainbow Precision ...

Silicone Lubricants
ENGINEERING DATA
Silicone products are useful over a wide temperature range (-100° to 400° F) but do not have the film strength of
petroleum types and other synthetics. It has become customary in the instrument and miniature bearing industry,
in recent years to derate the dynamic load rating (Cr) of a bearing to 1/3 of the value shown in this catalog if a
silicone product is used. Some silicones have a very low vapor pressure (10 -6 Torr) and can be used for bearing
vacuum applications above this pressure.
Perflourinated Polyether
Oils and greases of this type have found wide use where high temperature stability, chemical inertness, or low
vapor pressure (10 -9 Torr), are required. This specialty lubricant does not have the film strength of a petroleum
or diester product. However, it does have better film strength than silicone lubricants.
LUBRICATION METHODS
Grease packing to approximately 25% of a ball bearing’s free volume is PEER’s most common method of
lubrication. In some instances, customers have requested that bearings be lubricated 100% full of grease.
It causes shearing, heat buildup and deterioration through constant churning which can ultimately result in
bearing failure.
OPERATION SPEED
When petroleum or synthetic ester oils are used, the limiting speed is dictated by the ball cage material and
design or the centrifugal ball loads rather than by the lubricant.
Lubricant for Commercial and Military Specifications
Lubricants can be designated by the customer to meet a particular specification. We have included a table of
widely used greases and some of their most important characteristics. All commercial oil and grease lubricants
applicable to ball bearings are readily available at PEER.
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