These press fi t self-lubricating bushings are manufactured from high 
quality self lubricated aluminum bronze material and are ideally suited for 
running with commercial and precision posts. 
 Self-lubricating bushings contain graphite plugs which are impregnated 
with oil. When the bushings reach 80-90°F as a result of friction between 
the bushing and guide post, oil is drawn from the plug thus lubricating the 
wear surface. A dark smear pattern is created on the wear surface as the 
oil and graphite are imbedded into the bronze or steel grain. This provides 
the lubrication necessary for continuous performance of the tool.