New lathe oil question

[verbotenwhisky]

im shopping lathes right now. too many options out there in the 12-14 inch range and have a lot of thinking to do. but most of the gear head lathes reccomend iso 32 oil for the headstock. when i look for local sources for iso 32 oil i get hydraulic oil... is this the same thing?

Yes, Mine is a PM1236 and it takes ISO 68, when I quizzed Precision Mathews they told me to use Hydraulic oil....

 

[verbotenwhisky]

It is called a hydraulic oil, But it is used in turbines and machinery, If you want to use tractor fluid in your lathe, That's fine, If hydraulic fluid you get at tractor supply was ok to use in the headstocks, Don't you think the manufacturer would say that in the manual? They give specific oil requirements that have different additive packages in them I'm sure my Ford 5000 Diesel Tractor does not call for Mobil DTE because it is different.

And Mobil DTE 20 is not the same as Mobil DTE light or Mobil DTE Medium.

View attachment 488462

At the end of the day its all about the specs....

 

[Harry Knutz]

A long time ago I had to replace spindle bearings on a lathe I got cheap because the original owner put 90wt gear oil in the headstock. He was was an older machinist who used very old machines that called for 90 wt. So he assumed this lathe, (Late 80's Enco) used the same oil, Had he checked the manual, His lathe would not have failed. This lathe had a small sheet metal box at top inside the headstock with a hole in it that had a vinyl hose attached to it that fed oil to the front bearing. Needless to say, No oil ever splashed up there to run down to the bearing.

Japanese Nachi Bearings are not that cheap, Plus it's a pretty good job to replace them along with the races. I think I will use what the manual calls for even if it costs more.

 

[G-ManBart]

It is called a hydraulic oil, But it is used in turbines and machinery, If you want to use tractor fluid in your lathe, That's fine, If hydraulic fluid you get at tractor supply was ok to use in the headstocks, Don't you think the manufacturer would say that in the manual? They give specific oil requirements that have different additive packages in them I'm sure my Ford 5000 Diesel Tractor does not call for Mobil DTE because it is different.

And Mobil DTE 20 is not the same as Mobil DTE light or Mobil DTE Medium.

It's called hydraulic oil, because it is hydraulic oil. You said "I know a lot of people use Hydraulic oil, But it's not the right stuff." That is an incorrect statement. In most cases, the correct oils listed for lathe headstocks are absolutely hydraulic oils. There are a variety of different hydraulic oil types. Nobody said anything about generic universal tractor fluid type oil as that has to work with wet braking systems in most cases. Nobody said anything about "DTE 20", which isn't an actual oil. It's the DTE 20 Series of oils I mentioned which are antiwear hydraulic oils often listed for lathe headstocks.

 

[Harry Knutz]

This is from PM-1340 T manual, It specifies the oil I showed, Which is Mobil DTE Circulating Oil.

 

[Nesse1]

First of all a hydraulic system has bearings, precise pump tolerances and a major dislike for impurities.
" manufactured from highly refined TURBINE oil stocks"
DTE is what has been called for in the headstocks of most machine tools for the last 50 years.
I personally feel it is over priced and any quality name brand oil of the correct rating will work just fine.
Another note, when I worked for companies during depressed economic times I had to make the most of my maintenance budget,
I used one viscosity of locally blended hydraulic oil, one viscosity of locally blended way oil ( which was pretty much hydraulic oil with a tactifier) one viscosity of high speed spindle oil.
We so no issues due to my oil choices.....
We made landing gear for military and non military airplanes.View attachment 488461

The oils referenced here as "named" DTE, are the recirculating oil type. Not the hydraulic oil type

Mobil DTE™ Oil Named Series
Mobil Industrial , United States
Premium Performance Circulating Lubricants

 

[ChazzC]

Funny story, my daughter messaged me this morning because she had her car at the dealer for a recall and they wanted to sell her all kinds of preventative maintenance that was way above and beyond even what her owners manual recommended.

@oogenshire Advance apologies for going sideways.

My dealer’s service department insists on trying to use the “Severe Conditions” maintenance schedule for our vehicles (don’t live in a bug city, drive in dusty conditions, tow anything) using the defined usage on the paperwork in GM’s system, claiming they can’t change it (one of these days I’ll get around to calling GM about this), so I keep an enlarged copy of the “Normal” maintenance schedule in the glove compartment.

 

[Nesse1]

@oogenshire Advance apologies for going sideways.

My dealer’s service department insists on trying to use the “Severe Conditions” maintenance schedule for our vehicles (don’t live in a bug city, drive in dusty conditions, tow anything) using the defined usage on the paperwork in GM’s system, claiming they can’t change it (one of these days I’ll get around to calling GM about this), so I keep an enlarged copy of the “Normal” maintenance schedule in the glove compartment.

Oh boy! A motor vehicle "oil" reference! That's even more a rathole than this thread is turning into!

Try...https://bobistheoilguy.com/forums/

I love that place. Even though science wins 90% of arguments there, there are still about half of the people that go by their gut opinion on when to change and with what.

 

[mksj]

Manual lathes are typically not critical as to the using hydraulic oil vs. circulating oil, and in many cases hydraulic oil includes gear lubrication. A hydraulic oil is both designed to lubricate and have minimal compressability where circulating gear oil and specific variants are designed for high load gears. The additives packs are different and there may be other variants in the properties as to anti-foaming, and miscibility with water. Many manufactures list an example of an oil, brand and series that is the standard to which to compare other oils to. There are tables which show equivalent oils between brands. The thing to point out with typical gear head lathes and such, is that they use straight cut gears that are not heavily loaded, so often you will see use of either an equivalent ISO hydraulic oil or a circulating gear oil. The oil brand is less critical in this application, as opposed to the correct ISO rating for the temperature range that the machine will experience. In particular with splash lubrication, too thick of an oil will not get the bearings as easily as a thinner oil, and also the higher the speed and/or colder temperatures typically the thinner the oil is used.

So there is some differences in the oils, but typically hydraulic oil is used interchangeably with circulating gear oil in most manual gear lathes. I have not heard of any deleterious effects of one vs. the other in this application. Using the wrong ISO rated oil as well as not changing the oil on a regular bases has more of an impact on longevity. Synthetic oils are often used where there is high usage and the need for extended oil change intervals, and in most cases should not be used with new machines until they are broken in. There is also the issue of clutch drives and synthetic oils being too slippery unless specified by the manufacturer.

The Mobil oils have gotten quite expensive, so alternative brands are more cost effective. I tend to use Miles hydraulic Oils sold by Zoro with free shipping on orders over $50. That along with frequent 20% off coupons makes buying a 5 gallon pale more attractive. My headstock takes over 2 gallons so the larger pale works for me. I use Vacuoline 1409 in my carriage because it also pumps the oil to my ways. You will find that many of the small lathe manufactures specify an ISO32 oil in the headstock and ISO68 in the carriage/gearbox. I assume PM/QMT uses an ISO68 in the headstock and gear trains to simplify stocking, but if colder climates I would opt. for a thinner oil. Eisen which has similar lathes specifies hydraulic oil, viscosity varies by lathe type and location, this is for their 1440EV which is their VFD model with a 2 speed headstock.

Is Hydraulic Oil Different from Circulating Oil?

I have pictures below of what I want to buy. I want to buy 1 gallon containers. I would really like to avoid buying a 5 gallon pail. I found 1 gallon Mobil DTE ISO 32, but it is hydraulic oil. I probably want to buy something that actually says circulating oil on the label.

www.hobby-machinist.com

 

[Harry Knutz]

From your first attachment. It say Mobil does not recommend using Mobil DTE 24 which is a Mobil DTE 20 series oil to replace Mobil DTE Light, DTE Light is a Circulating oil with a different additive package.

Quote:

1. The DTE Named Series IS NOT Mobil’s “lowest cost” oil. In fact DTE Light isabout 10% more expensive than DTE 24, even in 55 gallon drums. Both oils aremade from turbine quality feed stock. They differ primarily in the additives used.2. The DTE Names Series HAS NOT been discontinued. It was available inDecember 2009 when Mad Machinist posted this and it is available today. AFIK,Mobil has no plans to discontinue it.3. Mobil DOES NOT recommend DTE 24 as a direct replacement for DTE Light.(Call their lube tech support line at 1-800-443-9966 and ask them yourself.)


And in the 3rd attachment, It definitely differentiates Hyd oils from Circulating oils.