Thanks to particular solutions during the molding process, a film of pure polymer is formed on the molded components surfaces, which has high sliding properties. This factor, in synergy with light services, enables the Aleph series to work in absence of lubricant. Anyway the presence of a lubricant layer on the threaded spindle can extend the screw jacks life; for the lubricants choice make reference to what has been indicated in the correspondent paragraph in the screw jacks section (page 17). It should be reminded that the Aleph series does not foresee any oil plug.