# Atlas / Craftsman Machines: Note On Use Of Lubricants



## Mondo (Apr 20, 2016)

I became aware of this only recently:  
Do not use lubricants that contain sulfur, as in some greases and oils labeled as "EP," in contact with bronze bushings and bearings, or other copper-containing parts.  Here is why:

The sulfur in these lubricants reacts chemically with the copper in the bronze bearings and can cause corrosion, spalling, and premature bearing failure.

Google Search for "EP Grease and Copper Alloys" produced a number of hits, two notable documents are:

https://books.google.com/books?id=aE...alloys&f=false

and

http://www.machinerylubrication.com/...itives-effects

Checking the lubricants I use with my lathe I found none that fall into this category except the high-sulfur thread cutting oil I use for some machining operations. I will need to be cognizant of any spillage that may contact the bronze bearings in the apron mechanisms while I am using that as a machining lubricant.

Spiral_Chips


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## Round in circles (Apr 25, 2016)

I wonder if that is why some of the Zamack change gears & other Zamack parts have suffered deep crack crazing over time ?


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## pdentrem (Apr 25, 2016)

The cracking in the Zamack is due to Intergranular corrosion.


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## wa5cab (Apr 26, 2016)

Supposedly caused by some batches using Zinc of insufficient purety.


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## Mondo (Apr 26, 2016)

Although the ZAMAK contains copper, it is not specifically a copper alloy as are brasses and bronzes.  ZAMAK is a zinc alloy.

Spiral_Chips


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