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Installation Instructions

Ball screws must be lubricated to operate properly and achieve the rated life.  Ball screws should never be run dry.

Inspection Prior to Lubrication:

All ball screw assemblies should run smoothly throughout the entire stroke. If the torque is not uniform over the entire stroke:
  • Visually inspect the screw shaft for accumulations of foreign matter.
  • Using cleaning fluid or solvent, remove dirt from the ball grooves. Be sure to flush the ball nut assembly thoroughly.
  • Cycle the ball nut along the screw shaft several times. Wipe with a dry, lintless cloth and lubricate immediately.
  • If the assembly continues to operate erratically after cleaning, contact Thomson for further instructions.


The operating environment primarily determines the frequency and type of lubrication required by ball screws. The screw shaft should be inspected frequently and lubricated as required by the environmental conditions present. Lubricants can vary from instrument grade oil for dirty and heavy-dust environments to a good grade ball bearing grease for protected or clean environments.

Grease or oil can be applied directly to the screw threads near the root of the ball track. Some ball nut sizes are available with threaded lube holes for mounting lubrication fittings. For these ball nuts, the lubricant can be pumped directly into the nut. Please refer to the product specifications to verify which ball nuts have the threaded lube holes. It is recommended to use these nuts in conjunction with a wiper kit to contain the lubricant in the body of the nut.

Where the application requires operation at temperatures below 0° F, an instrument grade oil is recommended. Operating environments from 0° F to 180° F will require a good grade 10W30 oil. For assemblies with balls larger than 3/8 in. diameter, MIL G 3278 grease is recommended. Bearing grease is recommended for operating environments at nominally higher temperatures. In unprotected conditions, the lubricant is best applied with a lubricant-dampened cloth, taking care not to leave an excessive film thickness on the screw. Ball screws should never be run dry.

CAUTION: Where the screw is unprotected from airborne dirt, dust, etc., do not leave a heavy film of lubricant on the screw. Keep the screw shaft barely damp with lubricant. Inspect at regular intervals to be certain lubricating film is present.
For a more indepth look at lubrication follow the link to this article.
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