Engineered Bearing Surface For Rock Drilling Bit

A method for making a roller cone drill bit:

• (a) providing a rock bit body having at least one leg depending from said body, a bearing pin depending from said rock bit body, said bearing pin having an exterior contacting surface and a roller cone having a cone cavity, said cone cavity having an interior contacting surface, wherein the interior contacting surface of the cone rotatably engages the exterior contacting surface of the bearing pin;
• and
• (b) polishing at least one contacting surface by positioning an abrasive paste comprising aluminum oxide and a polymer between a polishing instrument and the at least one contacting surface and polishing the at least one contacting surface thereby reducing the surface roughness of the at least one contacting surface and imparting a polymer coating on the contacting surface.

A method for making a roller cone drill bit, the method comprising:

• (a) providing a rock bit body having at least one leg depending from said body, a bearing pin depending from said rock bit body, said bearing pin having an exterior contacting surface and a roller cone having a cone cavity, said cone cavity having an interior contacting surface, wherein the interior contacting surface of the cone rotatably engages the exterior contacting surface of the bearing pin;
• (b) polishing at least one contacting surface by positioning an abrasive paste comprising aluminum oxide and a polymer between a polishing instrument and the at least one contacting surface and polishing the at least one contacting surface thereby reducing the surface roughness of the at least one contacting surface to less than 10 micro-inches Ra;
• (c) imparting a polymer coating on the at least one contacting surface, the polymer coating having a thickness of between 4 and 10 mm and adhering to the at least one contacting surface with an adhesive strength of at least 100 kilograms per square centimeter;