These HG20 Linear Rails and Blocks were used in my CNC build.

Unfortunately the blocks did not move easily on the rails, after watching numerous videos on YouTube, it was time to disassemble the blocks carefully. So many suggest using all different types of lubrication, but I looked at the manufacturers suggestions and found that these suggestions were not quite correct.

I found something very close to the manufacturers recommendation, the ideal was Mobil SHC 639 and I found Mobil SHC 636 on Ebay. The SHC 639 is ISO 1000 and the SHC 636 is ISO 680.

Why? Unfortunately these lubrications are industrial in nature and are available in 55 gallon drums and is very costly. The lubrication found on Ebay was someone who repackaged the Mobil SHC 636 into 4oz bottles. It is used for Rigid Saws.

If you want to search, the terms to use are "Worm Drive Lubricant Oil 4oz Synthetic/OEM for RIDGID Saws".

Of course this is only a very brief observation of the difference in the the before and after, once the linear bearings were taken apart and properly cleaned. You can actually hear the difference, the repacked bearings run smoother. The before ones sound clunky and move haltingly.

My suggestion is if you purchase these Linear Rails and Bearings it's imperative to properly clean them and use the proper lubrication.

Good Luck!