Ball Screws should never be run without lubrication!
- Ball screw assemblies require proper lubrication to ensure long life and smooth operation.
- Running without lubrication may reduce the life by 90% or more!
- Ball screws and nuts ship with a rust preventative. It is not sufficient lubrication.
Lubricants are often taken for granted, but the right choice for each application ensures a ball screw that performs properly for its calculated life. Both oil and grease provide corrosion protection, but lubricant choice depends on evaluation of the advantages and disadvantages of each in the given application. The specific type of lubrication for a Ball Screw depends on various factors.
- Light loads and high speeds do well with a machine oil or low viscosity grease.
- Medium loads and speeds do well with NLGI 1 or 2 grease
- High loads may require a grease with an EP2 additive. The EP is Extreme Pressure and uses special additives to prevent the grease from breaking down under high pressures. This type of grease will give the steel shafts a dull appearance.
Careful monitoring of the application is required to develop a good preventative maintenance schedule. The screws should be kept with a slight film of grease/oil at all times. It should feel slick to the touch but not dripping. You can lubricate the screw by applying grease to the OD of the screw and running the nut back and forth or via the lubrication fitting if the nut has one. DO NOT use any type of dry lubricant (PTFE powder, graphite powder, etc.) with any recirculating ball or roller type of bearing. While these lubricants are good for sliding motion, they do very little to aid rolling friction.