# Lubricating a mill



## wm460 (Jun 3, 2015)

I got the Sieg SX3  striped down and cleaned ready to re assemble.

What sort of grease do I use on the lead screw?

What oil and grease should I lubricate it with.

Must be available in Aust


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## Swifty (Jun 3, 2015)

I've never used grease on a lead screw, just a lubricating oil. I would not use motor oil at all, I fill my oil can up with hydraulic oil that I use in the lathe headstock.

Paul.


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## Blogwitch (Jun 3, 2015)

Hi,
I have used for many years a copper based grease for all greasing situations such as this.
I find it doesn't throw off or pick up swarf like most other greases. I don't know if it correct, but my leadscrew nuts have lasted really well with it.

I do know a chap who swears by using a Rocol tapping compound (which looks like a thick grease), he states that it is a very high pressure lubricant, so should work with anything that requires high pressures, which a leadscrew and nut are.

Normally people just slap on a bit of general purpose grease, but I am sure that by using peoples knowledge about specialised greases, life spans of high pressure items such as yours can be significantly increased.

For other high pressure areas, such as dovetails and slideways, a 68 grade of oil should be used as it creates a very close tolerance film of lubricant between the sliding parts (approx 0.002" thick), which a thinner oil cannot achieve and retain.

Hope this helps

John


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## Swifty (Jun 3, 2015)

A lot of the older Bridgeport mills had a mark on the X axis slide that you had to align, then undo a grub screw in the middle of the centre T slot so you could oil the Y axis nut and spindle. My Bridgeport clone has a hand operated oil pump on the side taking oil to the axis nuts and sideways.

Paul.


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## kvom (Jun 3, 2015)

Way oil on slides for me.


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## barnesrickw (Jun 3, 2015)

Whatever is in that little red can out in my shed.


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## XD351 (Jun 3, 2015)

Chainsaw bar oil .


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## pete (Jun 4, 2015)

Think about it logically. While there somehow might be a very few almost unknown and old/rare machine tool manufacturer's who may or might recommend any kind of grease as lubrication for somewhere on there machines, I've yet to ever see that in print so far. It's ALWAY'S oil and usually the same oil as what they recommend for the slides. Way oil,and only way oil. Obviously the feed screws and nut's will slowly wear over time, that does create contamination within the lubrication from fine metal wear particles from the feed screws and the nut. Running that contamination that your not flushing out with the grease will just greatly accelerate the wear and tear on your machine tools. Oil tends to flush out those wear particles. And grease lubrication tends to fairly quickly get squeezed out or move away from the high pressure point's and the needed lubrication areas. Oil will at least mostly flush any contamination out. Even air bore dust, grinding dust, or whatever will tend to get drawn into anything that's grease lubricated. But every time you add more oil it will usually flush or wash out that contamination if your not being dirt cheap with the oil application. 

I've spent a very long time in my career operating some extremely expensive large engines, and a lot of it in very remote locations. Not one of the company's I worked for EVER tried to cut corners on the recommended engine oil or ANY lubrication point's. Going against the manufactuer's lubrication recommendation's would be moronic. 

Machine tools either used or new, and even the cheaper Chinese machine tools are fairly expensive to buy for almost any of us. Why would you try and pinch pennies using anything that isn't what's recommended? Hell depending on the exact composition of a tools bronze bushing's it's also quite possible that using high detergent motor oil will slowly destroy those bushings. Don't believe me? Then do your own research. But I can say that grease of any kind isn't even close to an intelligent idea for any machine tool that I know of. All of the equipment I do have has manufacturer's recommendation's of way oil for way's, feed, and leadscrew's, and spindle oil in the mill's head. Anyone who thinks they know better than the oil industry's engineer's and can concoct there very own formulation and then say that's what you need sure need's to explain there finding's to the machine tool manufactuer's and then the oil engineer's. There's some very definite and logical reasons for exactly why the manufacturer's of your machine tool's do list what they think is the very best lubrication.    

Pete


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## Cogsy (Jun 4, 2015)

pete said:


> I can say that grease of any kind isn't even close to an intelligent idea for any machine tool that I know of


 
I used to have to calculate lubrication recommendations for new bearing installations for a large bearing manufacturer (local projects, not for the whole company) and there are definitely places where grease is preferable to oil. 

Grease is simply oil held in a 'soap' and the oil is released for lubrication under the correct conditions. One of these conditions is high or extreme contact pressures. A correctly selected grease will release some oil and provide correct lubrication at these extreme pressures (although they won't function well at low loads), whereas oil on it's own will not be able to maintain the oil film and the parts will contact and be damaged or destroyed.

A properly greased bearing will also generally run cooler than a bearing in an oil bath, due to reduced 'pumping' action of the lubricant and reduced friction of the lubricant as well (oil and grease do both create drag friction in a bearing - think about hitting a deep puddle of water in your car, that drag you feel increases as the medium gets thicker).

I also know of many systems using a continuous grease purge to flush contamination out bearings, especially in high dust or dirty environments.

I wholeheartedly agree that the manufacturers recommendations be followed but I do see where that specification may be for grease rather than oil in some instances.


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## Blogwitch (Jun 4, 2015)

Pete, I don't agree with most of what you have written purely because you just quoted way oil with no explanation of what it actually is, and Cogsy, I do agree with your comments, as that is the same as I have learnt in the years I was involved with aircraft and industry.

But also, manufacturers have to be blamed at times. Myford actually fitted grease nipples to their earlier lathe heads, so people automatically pumped grease into them. Unfortunately, grease is not the ideal thing to fill bearings up with, they tend to hydraulic and damage the rollers. I am sure they were fitted so that Myford could also sell you their expensive grease point fitting oil gun. If the bearing protectors on the head were correct (as my Atlas ones were), then the bearings only ran about 25% full when filled with oil as the excess drained away through strategically placed cutouts in the bearing protector shields.

As I stated about lubricating the screws, grease really is the only way to do it as it holds the lubrication in a suspension inside the component parts, which if just oil based would soon drain themselves away whilst in use due to the pressures involved.

Just a little info in case you misunderstood my recommendations for oil.

Almost all machine manufacturers quote way oil as an ISO 68 grade, they should NOT quote just way oil because that can be open to misinterpretation.

For general lubrication and for the majority of geared heads for lathes, they invariably quote an ISO 32 oil, which just happens to be a standard grade of hydraulic fluid used by farmers all over the world for their machinery.

Some manufacturers try to jump on the maximum profits bandwagon (Myford for one) and quote trade named products, but when they are researched, they usually come out as the same pair as I have quoted.
If a supplier is just calling it way oil or gearbox oil, then ask them what the ISO number is before ordering.

If you are used to another method of viscocity quoting, then this might help

http://www.doolittleoil.com/faq/viscosity-sae-iso-or-agma


John


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## DJP (Jun 4, 2015)

My old machines from the 1940s drink oil. Before each start up I fill up little spring capped reservoirs and put a drop into tiny holes that wet bushings. It's been like that since day one for the machines and they still do work for me. 

So with oil can in hand I dutifully lubricate everything before starting. My bench is oily as a result but my view is that if you are not getting oil spots on your shirt front, you are not applying enough oil.

Just apply lots of oil and run the machine. I'm sure that it will last and leave the grease for sealed bearings.


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## Silvergoose (Jun 4, 2015)

It seems that oils and/lubrication topics are the same weather it is about machines, motorcycles or any number of machines that do work.
The fact remains, Lube and keep all surfaces clean. What ever works for you is the best you can do.

Good Luck


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## barnesrickw (Jun 4, 2015)

Silvergoose said:


> It seems that oils and/lubrication topics are the same weather it is about machines, motorcycles or any number of machines that do work.
> The fact remains, Lube and keep all surfaces clean. What ever works for you is the best you can do.
> 
> Good Luck




What he said.


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## pete (Jun 5, 2015)

barnesrickw said:


> What he said.[/Q
> 
> NO!!!________________ not what he said at all.
> I'm sure as hell not a member here to score points or whatever. I'm trying to provide 100% correct and factual information, and only that. And certainly not ever what "I think" or even my best guesses. Exactly why do so many members here try to fight honest and factual information that shouldn't be subject to what you personally think? And especially so when someone obviously doesn't know there a** from a hole in the ground.
> ...


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## Blogwitch (Jun 5, 2015)

Pete,
I would suggest you get down off your high horse and READ AND UNDERSTAND what I posted about.

Your quote of way oil means absolutely nothing. Way oil can mean almost anything and without that specification can mean anything.

It is not a pissing contest, but a way of getting the correct information across so that people can understand it.

You say way oil, and within a few hours you will have people asking what it is, give them a grade of lubricant and they know instantly.

Then we get back to my knowledge. Nearly 50 years in all sorts of industries does give me fairly free reign to quote what I said, unfortunately, now that I am retired, I haven't kept up with lubrication requirements for the latest machinery, but I can guarantee you that what I have quoted already is relevent to all your workshop machinery. I have designed and built machines most probably larger than most peoples shops, and because of that I also had to specify maintenance schedules for such machines, and that included researching lubricants to ensure that the machine wasn't compromised in that department. In fact it was all that research which took longer than actually building them.

I hate people who start quoting their qualifications to gain one upmanship, as a lot of it is just paper orientated, but you have forced me into telling you some of mine to clarify things a little.

So please, settle down, and if you do have to get info across, try to give ALL information at the time, then discussions like this wouldn't be necessary.

John


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## bazmak (Jun 5, 2015)

For a nice friendly forum with anybody from a newby to Nasa engineers
i think your out of order Pete,not for what you said but how you said it 
Have a good day


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## DJP (Jun 5, 2015)

In this world of on-line forums where people communicate with their writing and composition skills it is so easy to appear disrespectful. Sentence structure alone can cause this as can the use of capital letters that denote shouting when the intent was emphasis.

Everyone needs to take time to read their draft post a few times before submitting it. The old business rule was that important memos were best read again the second day before sending. 

I respect the opinions and experiences of every member on this forum even though I may not agree because of my own experience. This sharing is not about power positioning and it's not about trolls that like to disrupt peaceful groups discussing their passion. We share because we are not competitive and in that spirit we need to continue respecting every comment as genuine and true for that member.

I have left a number of other forums specifically ones about a car brand or motorcycle model. They become too vicious and hurtful.

The good news is that eventually everyone gets a little older and the problem goes away.


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## Cogsy (Jun 5, 2015)

Pete, I don't know what product you mine for, but here in Western Australia we mine a fair portion of hard rock, in temperatures that can reach 55 degrees celsius, all of which has to pass through a crusher and/or ball mill of one type or another. All (or at least most) of the trunion and pinion bearings of these machines are grease lubricated and often grease sealed as well. Crusher bearing lubrication is especially critical due to the shock loads and vibration they are exposed to. Again, it is grease.

In addition to the dust associated with crushing operations, we have large areas of very fine dust called bulldust (as fine or finer than talc), which gets into everything. Of the hundreds or thousands of miles of conveyor systems in the mining industry I do not know of a single one that is not grease lubricated. Continuous grease purge systems are often in use on conveyors to exclude the dust, either in conjuction with a labyrinth or taconite sealing system. Although conveyors themselves are not composed of terribly expensive individual pieces, unscheduled shut downs cause lost production that can run into the millions of dollars very quickly, and are avoided at all costs.

I can appreciate that maybe things are done differently where you are, but over here, in extremely hostile environments, grease is a vitally important lubricant. 

Generally speaking, the only time we ever spec'd an oil lubricated bearing was for high speed applications. For ultra-high speeds sometimes even an oil mist.

Edit to add : In extremely cold environments (like inside of freezers or most of Canada in Winter) greases are often not a viable option either, especially the highly specialised types.


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## barnesrickw (Jun 5, 2015)

Dear Pete, the HAAS CNC machines I use at work come with one system that will feed oil, another for grease to prevent oil from getting in the cooling fluid.  The CNC I used at another job used grease only because it was for woodworking, and had no cooling system.  You are unaware of any knowledge I have on any subject, my professional background, or anything else that qualifies you to determine if I do indeed know my ass from a hole in the ground.  I however have an idea that you are rude and hard to get along with.  Have a good day.


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## Wizard69 (Jun 7, 2015)

Speaking of lubrication, at work there are all sorts of devices using profile linear rails.   Some are greased, some oiled, many automatically.  Both do wonders for rail life and this is quickly proven if a lube line breaks or is plugged.  Since a few of these rails have to be run absolutely dry you can see a dramatic difference in bearing life.  In the end any lubrication is better than none.


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