Metal Working Fluid. Is It Like Cutting Oil?

"Metal Working Fluid" by definition is a fluid that aids metal working operations, there are many designed for specific machining applications and materials. Drawing oil for deep drawing, tapping fluids, fluids used in roll forming and so on.

That is a water soluble flood coolant, useful for milling, turning, drilling, reaming and grinding, not so good for tapping or broaching. Often when a manufacturer recommends a particular coolant not be used on non-ferrous metals it is because they will stain the finish of aluminum and brass parts. It is never recommended to use a water soluble coolant on magnesium as the water will react with magnesium dust and small chips releasing hydrogen which burns rather vigorously. Try it on aluminum, if it doesn't stain it then no problem.

Remember that many of these types of products are developed for manufacturing where hundreds of parts may be covered with coolant for most of a work day before being cleaned. Tap water will stain bright aluminum if left on it long enough, which isn't terribly long.
 
I use a very similar product in my no fog mister. Really improves tool life. I find a bit richer is better, like 7%. 20:1 is 5%
 
It is my understanding that water based fluids are intended for high production requirements where the machining rate and tool life is maximized by the rapid removal of the heat generated by the cut. Water is the coolant, the more the better hence the use of flood systems. The 5% of other stuff includes an all important rust preventative and a bit of lube maybe.

Cutting oil is intended to reduce friction between tool and work so there is less heat generated. Oil however is not as good a coolant as water.

Coolants and lubricants are especially significant when using a HSS tool because of its lower tolerance for heat. Carbides and 'crobalt' tools have a higher heat threshold and can be run without lube or coolant for many hobbyist purposes.
Depending on the circumstances a lube may help improve the finish.

For my purposes, cutting oil is the most useful and I try to stick to one kind. That way it can be reused even if a bit of way oil gets mixed in. Alternating between oil and water based coolant makes a messy soup in the drain pan that is disgusting. Been there done that!
 
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Tozguy said:
Coolants and lubricants are especially significant when using a HSS tool because of its low tolerance for heat.
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HSS has an extremely high heat tolerance, and is actually hard to soften unless you follow a very specific cooling treatment. From what I understand it can cut while red hot.
 
OK. So this is basically a coolant. I admit I was a little confused by the "metal working fluid" title on the pails. I would like a homemade mister of some type one of theses days since I have air in my workspace, so I guess it will remain unopened, and I'll store it away until then. I paid about 50 cents a liter for the stuff, (2 unopened 5 gal pails) so that is good. Not quite what I thought it was but I'm still glad I bought it. Thanks everyone!
 
Andre said:
HSS has an extremely high heat tolerance, and is actually hard to soften unless you follow a very specific cooling treatment. From what I understand it can cut while red hot.
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Carbide can cut while white hot. Also the very tip of a cutter can become much, much hotter than the body a few thousandths back. HSS can stand much more heat than tool steel but you can still overheat it.
 
This is a quote from a tool supplier:
"For turning very hard materials such as heat treated steel, Tungsten Carbide is the tool bit of choice. On the Rockwell hardness scale, Crobalt is about 62HRc, M42 HSS about 65HRc, and Tungsten Carbide in the 80+HRC range.
Even though M42 HSS is slightly harder at room temperature, its hardness drops at a quicker rate than Crobalt as it heats up, so would be softer at elevated working temperatures."

Speeds and feeds with carbide tools are usually multiples of those for HSS because of its higher heat tolerance. Steel chips from a HSS tool should be barely yellow whereas the same steel from a carbide tool can be blue.

Andre, I am curious about what material you were cutting with a red hot HSS tool.
 
ih8beingold said:
OK. So this is basically a coolant. I admit I was a little confused by the "metal working fluid" title on the pails. I would like a homemade mister of some type one of theses days since I have air in my workspace, so I guess it will remain unopened, and I'll store it away until then. I paid about 50 cents a liter for the stuff, (2 unopened 5 gal pails) so that is good. Not quite what I thought it was but I'm still glad I bought it. Thanks everyone!
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I don't recall where but somebody mentioned this place:

http://www.banggood.com/Mist-Coolan...CNC-Lathe-Milling-Drill-Machine-p-979642.html

I sent away for one and will eventually make a stand to use it as a drip system I think.
 
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