Anyone using spiral-tip taps for hand-tapping?

[Beerhippie]

I've been hand-tapping holes in steel, cast iron, stainless steel, aluminum, brass... the list goes on... for many years. I've always used "standard" plug taps. I'm sure you all know how that goes--half a turn, back off a half turn to "break the chip", make another half-turn, repeat until the tap clogs, back it out to blow the flutes clean--or just snap the tap off in the hole and start pulling out hair.

Well, I was doing my bored Youtube surfing thing the other night and watched a video of some guy ranting about how much better taper-tip taps were for hand-tapping than tapered or plug taps. Now, normally, I take this sort of thing with a pound of salt as so many videos like this are simple shilling for a product, but this guy seemed sincere and wasn't pushing any brand or product, just a style of tool.

I'd always thought that taper-tips were for machine tapping only.

So I laid about $8 on the line and ordered a two-flute taper-tip in 1/4"-20tpi, as that's my most-often used size. I've been using it for over a week now, mostly in steel and aluminum, and I'm sold.

In fact, my mind is somewhat blown! All these years, I've been beating my head against the wall 'cause NO ONE TOLD ME! This tap glides through metal when tapping a through-bored hole--no stopping to "break the chip", no need to clean the flutes.... The first time I tapped through over an inch of pure aluminum, I was convinced that I'd screwed up (again) and used a bit that was too large for the hole. Nope. It was right. The chips all were falling out the bottom of the hole and there was no clogging of the flutes at all.

Now I need an entire set from #6 to 1/2", NF and NC, plus metrics in the same range. That's gonna get expensive. Maybe I can sell my plug-taps to some sucker?

You all probably know all about this already, but I thought maybe there might be one person who doesn't--like me.

 

[Wiz02]

Thanks for the information, I tap a hole very infrequently and it is usually a pain.

 

[jayemm]

Are you talking about 'spiral point ' taps (also known as 'gun' taps)?

 

[cannuck]

I long ago learned how much safer it is to pre-tap with tapers and follow up to finish with plugs - or to finish shallow blind holes with a third cut from a bottoming tap in steel. Will usually do aluminum one shot with plugs, though. I bought everything from 6 to 1/2 in all 3 decent brand name stuff when they were relatively cheap. I seldom break on but occasionally wear one out and my eyes water when I have to replace them at today's prices. I find 2 things REALLY make life in the tap lane a lot safer: If at all possible, try to run the tap into the hole on same setup as drilling while clamped in drill press or mill. I start them with a tap chucked hand barely tight so it slips, so I have foolishly put of a tapping attachment for 40 years. What I DO do is put the correct tap drill in another hole in the tap rack beside the row of that size. Also keep Hangsturfers right beside tap and die drawer.

(on edit) I see you asked about hand tapping: all above applies IF you can start it a couple turns in same setup as drilling. Otherwise freehand all of the way and the taper taps seem to go in straighter and easier than trying to start straight with a plug tap.

 

[larry_g]

Never heard of a taper-tip tap? Are you talking gun taps or spiral tip? Can you link to the tap you bought and the vid you watched?

lg
no neat sig line

 

[whateg01]

I've no idea what you are calling a taper tip tap. A tapered tap still has to be backed up to break the chip. I can only assume, like jayemm that you mean spiral point taps which are great for through holes. I use them for blind holes too but it's a pain to get the chips out of the bottom. A spiral flute tap would really be better for that but ime they are a little more fragile.

 

[In The Doghouse]

Are you talking about 'spiral point ' taps (also known as 'gun' taps)?

Has to be this. They're much better especially in a through hole.

 

[Steve_P]

I assumed that he meant a (standard) tapered chamfer tip straight flute tap. Yes, I know it doesn't explain his excitement with them magically clearing chips, but whatever... maybe his old taps were junk and he bought a good one?

edit:

https://www.mcmaster.com/products/machine-taps/general-purpose-taps-9/

 

[Beerhippie]

I meant spiral-tip or -point taps. Fixed now.

The plug taps and taper taps I've been using for years were not junk. The spiral-tip just works much better.

Using the drill press to start the tap is a great idea and I use that when I can. Anyone want to volunteer to carry the drill press to where I need to drill and tap a hole in something in place in the brewery? Hold it up fifteen feet off the ground while I make a hole in something big and vertical?

Before someone suggests a magnetic-base DP: brewery equipment is almost exclusively 316L or 304L stainless--not ferromagnetic.

 

[larry_g]

Before someone suggests a magnetic-base DP: brewery equipment is almost exclusively 316L or 304L stainless--not ferromagnetic.

Industry I worked in was a lot of non ferromagnetic stuff also. We would clamp a suitable bit of steel plate to the part and then use the mag base from there. I have also used a Cole drill in the past to make holes in stuff.

lg
no neat sig line

 

[F-22]

The "gun point tip" tap needs to be used in a through-hole or a deep enough hole for the chips. It pushes them forward and through. The spiral flute tap pulls them out.



Used both by hand. Broke both by hand... The gun point design works very well by hand for sure. The spiral one loves to break if you put any odd forces on them.
At work, sometimes to save time we even strap it into a battery powered drill and have at it. *usually* it turns out okay, now and then we throw stuff away too...


but sometimes you also just need the 2 or 3 step hand tap.

 

[Beerhippie]

More than 90% of what I need to tap is through-bored. I use a bottoming tap a few times a year.

 

[teagueo]

You can hand tap with form taps (roll taps) as well (at least in smaller diameter threads).

Form taps don't cut and create chips - they force the material into place. They last a helluva lot longer than a typical sharp cutting tap.

Figured I'd throw it out there because I didn't know it was possible by hand.

 

[Beerhippie]

You can hand tap with form taps (roll taps) as well (at least in smaller diameter threads).

Form taps don't cut and create chips - they force the material into place. They last a helluva lot longer than a typical sharp cutting tap.

Figured I'd throw it out there because I didn't know it was possible by hand.

How do they perform in hard-to-tap metals like 316L stainless? That stuff is so hard to tap, I'll generally just weld on a threaded fitting for anything over about 3/16" thick--especially tapered NPT threads.

 

[teagueo]

How do they perform in hard-to-tap metals like 316L stainless? That stuff is so hard to tap, I'll generally just weld on a threaded fitting for anything over about 3/16" thick--especially tapered NPT threads.

Not sure about SS, I was tapping 3D printed Titanium - the most abrasive, gall-worthy stuff I've ever tapped. After a few parts, the tap coating wears off and it dulls. Once the tap starts squeaking and "sticking" it's pretty much over.

Went from getting 2-5 parts out of normal taps to over 13 with a form tap. The tap was around 100 bucks though....

Form taps sailed right through surprisingly. Not much difference in effort with the tap handle. This is only M2.3 threads btw.

I'm sure it'd work just was well with stainless but I've never seen form taps for NPT threads.

 

[SARG]

When I was an apprentice they were called gun taps & bottom taps ... start with the gun and finish with the bottom.

 

[Beerhippie]

Not sure about SS, I was tapping 3D printed Titanium - the most abrasive, gall-worthy stuff I've ever tapped. After a few parts, the tap coating wears off and it dulls. Once the tap starts squeaking and "sticking" it's pretty much over.

Went from getting 2-5 parts out of normal taps to over 13 with a form tap. The tap was around 100 bucks though....

Form taps sailed right through surprisingly. Not much difference in effort with the tap handle. This is only M2.3 threads btw.

I'm sure it'd work just was well with stainless but I've never seen form taps for NPT threads.

Not much out there tougher to tap--or work--than titanium.

But for $100....

 

[dr_clyde]

I pretty much only use spiral point or spiral flute taps.

I worked in a brewery for about 5 years in industrial maintenance and fabrication, so I've tapped my fair share of stainless.

Straight flute hand taps are pretty much worthless, I honestly don't know why people buy them. Cheap and they come in "sets" and I guess folks like that. HSS spiral point by Union Butterfield is my go -to for stainless and general tapping jobs. I use spiral flutes when I need to, but they are more fragile and are more likely to break on a hand tapping job vs a machine setup.

Form taps are great, but they do have some issues with stainless due to work hardening of the material as you tap it. If you're not dead straight and flooding it with coolant it can go bad quick. I prefer form taps for aluminum or soft steel where the increased thread strength is a big advantage and the material doesn't put up much of a fight.

 

[dutchgray]

I use all types of taps by hand if needed, but only machine type taps under power.

I do try to start any tap straight in the machine if the drilling was done by machine, it does make it easy.

I do discard any blunt taps though, much easier to break one when they don't cut properly. (Well they get re used for other things, good source of nicely ground round HSS stock)

 

[Beerhippie]

I pretty much only use spiral point or spiral flute taps.

I worked in a brewery for about 5 years in industrial maintenance and fabrication, so I've tapped my fair share of stainless.

Straight flute hand taps are pretty much worthless, I honestly don't know why people buy them. Cheap and they come in "sets" and I guess folks like that. HSS spiral point by Union Butterfield is my go -to for stainless and general tapping jobs. I use spiral flutes when I need to, but they are more fragile and are more likely to break on a hand tapping job vs a machine setup.

Form taps are great, but they do have some issues with stainless due to work hardening of the material as you tap it. If you're not dead straight and flooding it with coolant it can go bad quick. I prefer form taps for aluminum or soft steel where the increased thread strength is a big advantage and the material doesn't put up much of a fight.

Thanks. That was what I suspected for form taps in stainless.