Tap and Die Tips

[Indy_500]

I'm looking for tips on good/bad ways of using a tap and die set. I just picked up my first one. Do i really need to use actual threading oil? or can i use something else? Is there right/wrong ways of using these things?

Thanks,
Indy

 

[Stephenw]

I use tap magic for lube.

A little about tapping at the end of this video...

http://techtv.mit.edu/genres/24-how-to/videos/142-machine-shop-1

 

[MadMark]

Avoid taping dry, You can use any oil, but tap magic is probably the best.

When tapping, go half a turn forward, then reverse the tap for a quater turn to release the chip. then repeat.
You must do this for three flute taps. with two flute taps the chip comes out the bottom, so you don't have to reverse.

Small taps, no. 4 and 6 break very easily. You can actually see the tap stop turning and begin to twist. ( the oil helps here) If you see this, back it up a half turn to release the chip. You need to go slow and not be distracted.

If you know any machinists, ask them.

If you have any small taps to do in hard materials like stainless, you will break a tap, don't feel bad its part of the learning proces. just try not to do it in a workpiece that took hours to make.

 

[wreckercologist]

Tapmatic is probably the best for aluminum. Use whatever you have on steel. I usually use whatever spray can is handy (usually Zep Twister).

Buy or make yourself a tap guide. Speeds up tapping and helps prevent breakage.

Chamfer the holes to be tapped. It makes starting the tap easier and reduces breakage.

Know when to throw away a tap or die. When they are dull, they are more likely to break.

 

[bmxr4life87]

Patience always comes first! I follow my tap chart which tells me what size drillbit to use for what size hole (115 pc drill bit set comes in handy here) then I always chamfer the hole and clean both the tap and hole then generously apply lube to the tap! Use a guide if you have one (I need more of these) and go slowly! Half a turn in a quarter turn out and I completely back out after 3-5 revolutions and clean everything off and re lube! I always clean my taps off with brake cleaner then apply a light coat of penetrating oil to prevent rust! I use brute lube but that's what's provided by the shop although I do keep a stick of boelube around for stubborn situations. tap magic is some amazing stuff as well and lube is quite cheap compared to one tap being replaced so I always use a lot

 

[caseyjw]

Don't always trust the tap chart... depending on what material you are tapping into and how thick the material is, you want to go with different percent of threads. When you are tapping into stainless, you want a smaller percentage of thread depth because of the difficulty in tapping stainless.

When you are tapping into aluminum, I would recommend 75% thread depth.

Also, for the equipment that I work on any type of oil or cutting fluid is a no-no. We use isopropyl alcohol for loosening bolts and also for a tapping fluid. You have to keep re-applying it but it works well. It also helps to have a dedicated set of drill bits that are paired up with your taps. Also keep some tapered taps and bottom taps, never know when you will have to tap a blind hole

Casey

 

[caseyjw]

Also I forgot to mention, if you are going to be doing any thread cutting with dies, you need to get a thread gauge. Especially for metric type threads, tapping with the wrong thread pitch will destroy your fastener.

 

[scott37300]

Do you guys just use a countersink bit to chamfer the holes?

What do you use for guides? I have been tapping more and more holes lately. I have a nice matco master set so would like to do everything I can to do it right.

Indy, what brand taps you buy? I know you shop at HF a lot, I go out ther about once a week also. Taps are one thing I would not go cheap on. They are one of those things that are expensive for a reason. Assuming you bought an HF set they will be good for cleaning or restoring damaged threads but I wouldn't make to many new threas with them.

There is a lot of info out there on taps and dies. There are many kinds of taps. I have a master set of tappered taps in metric and standard. Also have a set of bottom taps in standard. These are for tapping holes with no bottoms. Also you need to make sure you get the right size drill bit, some are fractional and some are numbers and some are letters.

I will try to dig up some info I have read for you later.

 

[caseyjw]

I wouldn't deburr the holes until after you tap, and my makita works for a great guide

I mostly tap into hoffman pro line panels

1. Lay out everything and draw lots of lines with pencils
2. Starrett auto punch all the holes (usually 40-50)
3. Grab a tiny drill bit... usually a #40 or above and pre bore all the holes
4. Switch to 75% thread drill bit and do the holes again
5. Put the tap into my drill and grab a bottle of goop
6. Do the old in-out a whole bunch of times, occasionally blowing off the chips with air and reapplying goop

That's the fun stuff Once you get used to it and are brave enough, tapping with a drill is something you will wonder why you never did before

 

[scott37300]

double post

 

[wreckercologist]

Do you guys just use a countersink bit to chamfer the holes?

What do you use for guides? I have been tapping more and more holes lately. I have a nice matco master set so would like to do everything I can to do it right.

I use a standard 82 degree countersink.

http://www.garagejournal.com/forum/showthread.php?t=53603

This thread has a link to the guides I have. They are pretty reasonable to buy and work well. If a guy had access to a milling machine they would be childs play to make......

 

[scott37300]

Those are pretty nice and for 33 bucks I don't think you can go wrong.

I've tapped some thinner plate before, 3/16" or so and have had the tap go in on an angle. Think these things would really help out

 

[foul_ball]

another technique is to chuck the tap into a drill press and turn it by hand to keep it perpendicular as you start cutting threads

oh, also, try not to be the guy turning the tap with a crescent wrench. good tap handles or tap wrenches will help a lot, though if you're just chasing threads to clean them out, you might be able to get by with an appropriately sized 8 pt. socket and a speeder or sliding t-handle. I won't use a ratchet unless the threads are fairly deep and the tap has already been threaded in a few turns past full diameter of the cutting edges.

 

[mkirkpatrick]

After reading this I want to say thank you, it has been over 20 years since I really did any machining. It is amazing how much a person forgets over the years when you don't do it anymore, thank you very much for the refresher. I need some metric taps, don't use them much, but they are one of those things that when you need them you need them. Thanks again.

 

[wreckercologist]

I use these almost every day at work:

http://www.lislecorp.com/divisions/products/?product=398&division=1&category=11

http://www.lislecorp.com/divisions/products/?product=402&division=1&category=11

 

[lilredex]

Here is what works for me.

Some of my taps are higher quality and some are from Canadian Tire and Princess Auto. They all work, the trick is to develop a "feel" for the tapping process and stop before it breaks. Watch the tap and interpret the "feel". Advance 1/4 to half a turn, (depending upon the resistance felt) and back up often to clear the chips.

Used motor oil works well as a lubricant (and on the drill press too). Generally on sizes up to 1/2" my pilot hole will be two drill sizes (64ths) smaller........good enough in most cases. When the tap gets dull (or breaks off), no need to throw it away, just cut off the bottom 1/4 to 3/8" and you have essentially a new tap. that is the part that does most of the work. You now have a chance to form your new end style......taper, plug or bottoming.

I do a fair bit of tapping in my DIY projects and it is always my preference to just drilling straight holes. Can't remember the last time one broke off.

 

[Indy_500]

Thanks for all the tips guys. Yes i did get the HF set but i mostly got it for stripped threads. I may do a little bit of tapping my own holes but i don't know yet. I figured motor oil would be a good substitute.

Indy

(any more suggestions you guys got would still help, thanks)

 

[woody 73]

Wow very good information... I use a can of lard I think it is called crisco,it works well and keeps the rust at bay.

 

[wafrederick]

Do not buy the $20.00 sets,you get what you pay for.The $100.00 and up sets are the best out there.I like the hex dies better,you can use a socket with them.Matco makes a slick set of 5 deepwell dies just for messed up lug studs and automotive use.If anything has has been heated up with a torch,do not run a tap down to clean the threads out right away and let the piece cool down first.Exhaust manifolds are this way.If you can find them and most shops have them,spiral taps are the best taps out there.Have these taps at work,came from shops that were closed down and were given away for free.

 

[Hal]

Keep your good taps and dies JUST for cutting NEW threads. Have a beater set or purpose built rethreading set for cleaning out old rusty threads or getting the last bit of something you burned out with the torch.

 

[Stick Figure]

Just a warning, but i picked up a cheap set of HF tap handles for an experiment the other day. After having them chucked in the lathe for modification, i learned that while the tap handle itself was straight (at least to the naked eye) the actual collar that you tighten isn't anywhere close to centered. In other words i would be extra care full making sure things are straight when using them.

 

[iandh]

I'm a machinist by trade.

On soft metals, especially aluminum, the ideal fluid is highly viscous, WD-40 and kerosene both work well if you don't have a purpose made fluid... you are more worried about galling than you are about lubricating the cut and drawing frictional heat away.

On hard metals, you'd want to use nothing less than one of the medium tap fluids such as tapmagic, or in some cases dark cutting oil. There's more friction/heat generated and you need a heavy oil that will not break down under the pressure, and will also stay in place during cutting.

On holes in stainless, nearly every machinist I've met, including myself, goes several thousandths over the recommended tap drill size to releive stress on the tap. It reduces the chance of breaking, and gives a little more chip clearance. In the end, you usually end up with a better hole even though there is less meat.

 

[bamatj]

I'm a machinist by trade.

On soft metals, especially aluminum, the ideal fluid is highly viscous, WD-40 and kerosene both work well if you don't have a purpose made fluid... you are more worried about galling than you are about lubricating the cut and drawing frictional heat away.

On hard metals, you'd want to use nothing less than one of the medium tap fluids such as tapmagic, or in some cases dark cutting oil. There's more friction/heat generated and you need a heavy oil that will not break down under the pressure, and will also stay in place during cutting.

On holes in stainless, nearly every machinist I've met, including myself, goes several thousandths over the recommended tap drill size to releive stress on the tap. It reduces the chance of breaking, and gives a little more chip clearance. In the end, you usually end up with a better hole even though there is less meat.

This is good advice. When you get down to 6-32 and under threads, even a couple of thousandths can make a huge difference. I always open the holes up as much as they can be. I dont even want to think about how many 6-32 blind holes I have tapped in 17-4. Whats fun is when somebody slips up and a whole order gets heat treated and nobody has bottom tapped em lol.

 

[Teken]

Does anyone have any feed-back with respect to the GearWrench set that is being offered by them?

The whole system looks to be well thought out and the geared handle to me seems like such a simple idea, yet no one has ever come out with it!

Insight . . .

 

[wreckercologist]

I should also be noted that a twist drill will have a habit of cutting oversize anyway.

There's a cheap and dirty way to get more size without going up in drill size. Grind one flute of the drill longer than the other and it will drill oversize.

 

[beelsr]

the gearwrench ratcheting tap & die handle kit? i have the 5 piece - just the ratcheting handle, 2 tap holders, die holder and a regular tap handle (i think). I like it. The ratcheting took a few holes to get the rhythm down but it's got a nice feel to it....

 

[tweety652]

what i did to first start learning was get different scrap materials and start practicing. I broke a few taps but it gave me the "feel" you need to develope when doing tapping jobs that would cost me time & money compared to only the cost of the tap...i also used inexpensive taps to start my "practicing" and it's weird but i can "feel" it in my wrist when something isn't going right. As others have said, PATIENCE is the key!!! there is never a rush when you're making threads to hold something as that something could prove detrimental in the fastener doesn't hold.

 

[bamatj]

I have never liked the ratcheting handles, you just cant get the right feel for it, breaking the chip. On bigger taps with through holes I guess they would be ok, but not what I would prefer. But when you get down into the small taps in blind holes, you are just asking for trouble with a ratcheting handle. Speaking of getting the feel for it, sometimes a small tap will get into sort of a bind, and it just has that feel like its going to break. Then when it gives, it will feel just like it broke and will have a small ping or popping sound to it.Then it may not appear to be broke. When it does this though 99% of the time it is cracked, and you need to get it out of the hole carefully as you can. It will break easily after this and you need to start over with a different tap.

 

[Arne73]

...and for those oh **** moments, a set of tap extractors makes life so much easier.