# What Is Everyone Using For Mill Head Oil?



## kf4zht (Nov 18, 2015)

Manual says ISO68 or gear oil. Anyone got recommendations on what works best and hopefully is available locally?


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## Bob Korves (Nov 18, 2015)

ISO68 is a viscosity index.  It says nothing about the other properties of the oil.  "Gear oil" could be a whole lot of different things, not all of them good for a mill.  Assuming you are talking about a gear head milling machine, find some ISO68 hydraulic oil, preferably AW type (anti wear additives), or ISO68 spindle oil.  Hydraulic oil is sold at Tractor Supply and tractor dealers.  Spindle oil is available from machinery dealers and the usual suspects like ENCO, MSC, Travers, KBC, etc.


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## Bob Korves (Nov 18, 2015)

Oil company distributors are also a local source.


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## maker of things (Nov 20, 2015)

Bob is spot on, ISO 68 is slightly less viscous than SAE 30 oil (see chart below). I use hydraulic fluid for the anti wear and anti foam additives as Bob noted.  All auto parts/farm stores should have a variant on the shelf.  





I tried 80w90 gear oil in my mill but it foamed way too much.  My shop is not heated full time so my machines get below freezing in the winter.  The ISO 32 suits my climate (theoretically) better and is what is on the shelf so I would use it anyway.


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## Bob Korves (Nov 20, 2015)

Watch out for hypoid gear oils with EP additives, which contain sulfur compounds.  Those oils can corrode yellow metals (brass and copper.)  A lot of our gearboxes have yellow metals in them.
https://en.wikipedia.org/wiki/Gear_oil


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## profmason (Nov 21, 2015)

I run Mobil Vactra No2 ISO 68.  I am in So. Cal so the shop stays between 55 and 90 degrees year round.  I keep Vactra 2 and velocite 10 (ISO 22) for the mills and lathes. Enco stocks these and seems always have x% off and free shipping.  Molyibdinum disulfide grease for high pressure bearings and bushings.  We are a long way from if it sticks -- WD40.


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## joshua43214 (Nov 23, 2015)

I use NAPA AW68 which is spec
http://www.napaonline.com/Catalog/C...ulic-Fluid-5-GAL-AW68/_/R-FHQ85705_0076414146

I like it, it is low odor, and pretty sticky.


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