Is that is the same way We get oil impregnated brass?
A curiousity to me was how does the oil stay there

 

First 2 basic definitions.

Porosity is void space in a material such as a rock. Think of it like the holes in a sponge.

Permeability is the ability of a material to allow fluid to flow through it. Dependant on how well the pores are interconnected.

Metals like brass and bronze are slightly porous, just like rocks. From my understanding oil impregnated metals are placed in a vacuum chamber filled with oil. Vacuum chamber sucks out all of the air in the metal and the oil is allowed to fill that space. It stays there due to wetting action (tendency of a fluid to "stick" to another surface) and capillary action/wicking (think of a wick drawing oil up itself in an old lamp.

 

i just wondered if it was procsesed. It's just odd the oil is always there