Tapping fluids

Years ago we had some problems taping with some self locking taps and after breaking few we called the manufacturer. They asked us what we use for fluid and suggested using EASYFOMY. It is a foam in a spray bottle with a long thin nozzle. You use very little as the foam coats the tap evenly. We probably would not even bother but they sent us one bottle. Best stuff ever. We never buy anything else. Now for the ease of machining on CNC without being there I normally use coolant with 7% oil in it. I think it is called HOCUT? but I don't think it maters to much as we used different oils before. I use it on steel, SS and aluminum and have no problems with taps from #2 to 1". Jerry

HOCUT? Sounds like what happens when they're holding out on the proceeds.....

PV:

We run our regular water soluble coolant (Hangsterfer's S500), at about 12%. That is usually rich enough to tap alum, brass, normal steels, most stainless, etc. without problems. BUT, when we tap a few holes in something like Inconel, Hastaloy, work hardened 304, or the like, we manually brush on a fluid called "Microfinish" (comes in a 1 gal. can).

Before I'd be putting kerosene, or anything else, in your coolant I'd call your distributer and ask them what the likely result might be. Unless you're breaking taps in alum I wouldn't be considering extreme measures.

I thought someone would answer by now, but not, so, since this was one of my specialties at _American Machinist_:

TapFree is a mixture of a few petroleum distillates, one of which is chlorinated and one sulfurized. Those are your "active ingredients." The original stuff was something else: it contained 1,1,1 trichloroethane. That

The situation is similar to that with TapMagic. They had to take the nasty stuff out. Too bad; it really got into the intergranular structure of steel and reduced the shearing force a great deal. It didn't lubricate much, but it kept taps from breaking by reducing the tapping loads.

The chlorinated oil does some of the same thing but not as well. The sulfurized oil helps lubricate the extreme-pressure areas of the cut where most of the friction builds up. A lot of that comes in the follow-up cuts made by sequential teeth.

There are a few chemicals that are very effective at reducing that shearing force. One of them, maybe the best, is carbon tetrachloride. I still have a half bottle of it, used for tapping steel under extreme duress. Don't tell anybody I have it. And don't take this as a recommendation to use it. It is seriously dangerous. When I think about how many pints of fly-fishing dope I used to make out of it, with no precautions whatsoever...sheesh.

I don't know about the aluminum stuff. If you try some steel tapping fluid on aluminum, and if black foam immediately bubbles up out of the cut, you've got some of the old 1,1,1 trichloroethane tapping fluid. I have one can of that squirrelled away, too.

-- Ed Huntress

I was doing an aluminum job, so I had some polishing kerosene laying around..gave it a try. Next day every inch of my body that touched that kerosene burned.

And yes to what you were thinking. ouch.

screw Kerosene. After that I was ready to use aloe vera for cutting fluid.

I use MolyDee for serious tapping in steel, SS, titanium and such. I also use a wax stick (Castrol makes a good one) which I pre-apply to the tap as the tool sits in the toolchanger (usually good for a couple holes before re-applying). CNC coolant is notably not a very good tapping lubricant. Some are better than others.

This is the very good / very bad stuff:

When one has decided on a tapping fluid (a liquid in this scenario), does it make sense to put it in a can, and have the vmc dip the tap into it, before the tapping cycle? I believe there was a post or two on this some time ago, but don't recall how common a procedure this was. Do production shops in fact do this?

If so, how deep should the tap be immersed in the fluid, and how often? Every hole? Every other hole?

Apropos of Vinny's reaction to kerosene (and some also object to the smell), WD 40 comes in gallon cans (about $13/gal at HD, a year or so ago), and doesn't seem to have kerosene's harshness or smell.

And here's another Q:

Is a good tapping fluid necessarily just as good in form tapping as cut tapping?

========== The stuff that gushes out of the hose and onto a cutting tool has several functions. Depending on what the machining problems are the rank order will change.

In no particular order:

(1) The fluid physical removes the swarf/chips from the cutting area.

(2) The fluid convects excessive heat from the workpiece and tool.

(3) The fluid provides lubrication to promote easy chip flow, for example up the flutes on a drill bit

(4) The fluid acts as an anti weld/solder agent by chemically altering the surfaces of the workpiece and/or the tool.

(there are others)

So the choice of "coolant" depends on what the most pressing problem is.

As for dipping the tap in a VMC, I have seen this done, but mainly as a patch. Most likely another coolant, and possibly a different type of tap would have been better, but the runs were small and the lead times short, i.e. use the taps on hand. This is a quick fix, but adds to the cycle time, and is one more thing for the operator to check. Unless you are having some sort of tapping problem, why bother?, and other solutions such as reducing the rpm may be adequate.

Also the question about the difference in "coolants" between roll form and cut tapping. As the physical process is different, i.e. metal displacement with no chip generation v. metal cutting removal with chip generation, most likely the *OPTIMAL* fluid will be different. Will the stuff you are using be "good enough?" No one knows. Much will depend on the production volumes [i.e. simply slowing down the rpm may be adequate for short/small runs] and other factors such as thread depth and tap surface treatment. [You are aware that there is a *BIG* difference in the tap drill size for cut and formed threads.]

Unka' George [George McDuffee]

------------------------------------------- He that will not apply new remedies, must expect new evils: for Time is the greatest innovator: and if Time, of course, alter things to the worse, and wisdom and counsel shall not alter them to the better, what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman. Essays, "Of Innovations" (1597-1625).

fly-fishing

If you wanting to get rid of it maybe there's a Boeing parking lot nearby...

That can is sealed with silicone caulk and tape, and kept on a back shelf for emergencies...along with the carbon tet and a few other chemicals that probably could get me thrown in jail if I brought them into the light of day. It's right behind the four-pound bottle of mercury.

-- Ed Huntress

Ed - That is the reason why I skipped on the gallon of hydrofluoric acid as we shut down a small semi-house. Wonderful to have when needed, but it will liquefy the bones in your body! First is the knuckles.

It and the flask of mercury stayed. My flip/chart Has mat spiral booklet is with me as is my large 4" 3-ring binder with docs.

I'd rather have a doc on a chemical I don't have or use than not have one and need one quickly.

The story I remember is from a retired man in San Jose. He passed on and the house was donated to an org. They were inspecting it for sale when one of them backed out of the old 1 car garage. The back section was filled with boxes of very old dynamite. He was a blaster that helped create some mines and wine storage area. Kept some around to long until it got dangerous. He had lost his mind in the process...

That was a day for the rough and ready guys in Fire, police, ATF, etc...

Mart>

Yeah, that does concern me. If I kick the bucket, it could cause my wife some trouble, even though the quantities I have are trivial. I'll probably use up the tapping fluid, which I've saved for the occassion when I might have to tap some hardened steel. That hasn't happened for years, though.

I'd like to know the legal status on the mercury now. I got that for amalgamating the lead in the muzzle brake of my Hi-Standard Supermatic, which collects lead like there's no tomorrow. I do have a couple of lifetimes' supply, however.

-- Ed Huntress

I hope that drill chuck is made in China...

There *are* Albrecht chucks made with dimond impregnated jaws for gripping hard tool shanks like taps. However, unless this is a locking version (they do exist), I see problems when it comes time to back the tap out -- Albrecht chucks release readily in reverse. :-)

Enjoy, DoN.