machine oil vs ND oil
 

Can't seem to find out the difference between the two. I have a lathe that calls for machine oil in the viscosity SUV 100 & 240. The best I can tell is 100=10W and 240=20W. Question 1; Is this correct? 2; Is ND oil any different than machine oil. Thought some of the oil experts on here would know. Thanks.

Re: machine oil vs ND oil
 

A Google search for Machine oil yields this.
https://www.mscdirect.com/browse/tn/...navid=12107418

Contact the manufacturer of your lathe for best results.

Re: machine oil vs ND oil
 

I believe it is SUS not SUV. SUS is saybolt universal seconds an obsolete measure of oil viscosity. SUS @ 100F or SUS at 210F. The modern metric unit of viscosity is cST or centi-Stokes at 40C or 100C.

Read your manual again carefully for the correct viscosity.

Re: machine oil vs ND oil
 

Story Time I was cleaning out a garage and had some nice clean oil in barrel.
I figured I would change the oil in my car. After a while the car was missing gave it tune up new plugs. I changed the oil again with Napa oil and car ran good.
What I was using was cutting oil and doesn't burn.

Re: machine oil vs ND oil
 

I read the manual! As I said it calls for SUS 100 and 240. I think that = 10 and 20 weight oil. As for question 2. What is the difference between machine oil and 10 or 20 weight non detergent oil?

Re: machine oil vs ND oil
 

Some of the difference is an engine oil is intended to keep a film on the metal surfaces and when it is hot it will smoke and it does not cool as well as cutting oil.

"Lubricating oils have strong bonds between the atoms
which are depended upon to keep the molecules from shearing
in operation. Think lots of teeny ball bearings between
the metal surfaces. Strong ball bearings. Oil manufacturers
go to great lengths to keep their oil from shearing under
high pressure and temperature.

Now cutting fluids are an entirely different matter.
Cutting fluids are designed to carry heat away, and to
allow the molecules to shear into pieces so metal-on-metal
contact can happen, and cutting can occur. One way this
is done can be seen in my favorite cutting fluid, lard
oil. It's an animal fat with weak interatomic bonds.

But make no mistake, there are *huge* differences in
chemistry between lube oils and cutting fluids. Motor
oil is an especially bad choice for a cutting fluid.
Look around at any shop you see, how many professional
shops use motor oil as a cutting fluid, and how many
use a purpose-engineered material for this?"

Re: machine oil vs ND oil
 

We used 20w non detergent motor oil to lubricate south bend lathes. (Lube the moving parts of the machine) not for cutting oil.

Re: machine oil vs ND oil
 

That's what I was wondering, cutting oil or gear lubrication? I would also think a 20w oil would work for gear lubrication.

Re: machine oil vs ND oil
 

I think skidmarks answered my question. I know the difference between cutting oil and lub. oil. I have been using 20 weight non detergent oil for lubrication but, didn't know if is OK in place of "machine" oil. I too have a South Bend lathe. Still would like to know the difference in the two oils.

Re: machine oil vs ND oil
 

What is the issue with getting machine oil 100 and 240 i can get them here as easy as any oil ?
I use 68 mostly but one of the machines calls for 100.
I call it way oil cause its used for for pressure feeding the ways of the lathes and the mills.
I would never ever put anything else then the best brand way oil i can get in my machines...i like them to much.
If it´s the gearbox oil you need that wouldn´t worry me to much to exchange for any good gear/ motor oil.
I´m being a bit fuzzy around my machines and pamper them to much...

Re: machine oil vs ND oil
 

The old southbends that we have just have drip cups on all the lube points of the lathe. The exposed gears on the headstock that power the lead screw i used the open chain gear lube in a aerosol can

Re: machine oil vs ND oil
 

My old Clausing uses two different grades of hydraulic oil when going by original specs. One viscosity for the head stock and another for the apron and gear box. I use Mobil DTE 24 & 26. It just depends on what lathe you have as to cross reference for modern oils. The older the lathe, the more obsolete the original lubricant specs will be. Practical Machinist is a good place to check if you can't find the specs.