Know for being very good variety self lubricating mechanical plastics is Natural Extruded Natural Nylon type 6/6 material. This grade of plastic has been available for decades.

Dupont Black Extruded Nylon type 6/6

Nylon material is a common Engineering grade plastic material. Known for abrasion resistance is frequently chosen for critical needs like the toughest and strongest rope.  If Nylon is a material you would like to know more about simply click here, %LINK%
This exceptional material excels with extended use and are typical when using Nylon. Nylon has one of the widest ranges of sizes and shapes, including thick plate, thin sheet. The Black Cast Nylon type 66 materials are produced in a massive size range.

Considering using Delrin Homopolymer vs. Acetal Copolymer

Performance Plastic materials

extruded nylon rod