Help: Broken Tap in Flight Hardware

[Beowulf]

GJ family,

I need some help. I have a space flight piece of hardware that has a broken #2 tap in copper. This is a two flute tap. We are able to get it to wiggle 1/4 turn but have no access to grab any portion of the tap with current tools. Sadly, machine, EDM....etc on flight hardware is a big no no. I can tell this will easily come out with the correct type of extractor. Sadly, my schedule does not allow for custom tooling. Adding to insult, the removal of this part would require a huge disassembly process that has big risks. Thought I'd throw it out there to the group to see if anyone has thoughts. They were only chasing the threads and not cutting so I don't think it is too stuck.

The #2 size is what is killing me.



Does anyone know of a tool like these, but for 2 flute?



or even something like this?

 

[vwpieces]

I recently bought a Walton 3 flute to remove a broken M5 tap. It worked... perhaps a 4 flute only using 2 pins will getr done.
Good luck.

 

[APEowner]

That *****. #2 is really small. You might be able to stick some tweazers in there and turn them with a pair of pliers.

 

[larry_g]

Me personally I would be grinding points on some needle nose pliers to fit into the space. If at all possible turn the piece upside down so that any loose particles can fall out of the hole. Gravity is sometimes a great tool.

lg
no neat sig line

 

[BrandonV]

Surgical forceps come to mind.

 

[teagueo]

The above replies should work if it's loose...I'd add lubricant if possible.

I'm in the process of dissolving M2.3 x 0.4 mm taps broken off in a blind hole, Titanium ("NOT FOR FLIGHT" parts) using acid. Probably a no go on your Copper parts, but just throwing it out there.

 

[KnurledNut]

The #2 size is what is killing me.

#2-56?
If so thats only a #50 drill size or .070" hole.
Maybe try persuading it with a fine dental pick or needle?

 

[micromind]

Might be too small but if you can cut a kerf in the end of a rod that's slightly smaller than the hole, it might come out.

 

[Beowulf]

Thank you everyone. I'll share everything with the engineers and see what we can do. I'll let you know what ultimately works.

 

[Beowulf]

Me personally I would be grinding points on some needle nose pliers to fit into the space. If at all possible turn the piece upside down so that any loose particles can fall out of the hole. Gravity is sometimes a great tool.

lg
no neat sig line

Tried this one and the points broke off.

I think we'll try some titanium tweezers.

 

[Bubba Fett]

Could you possibly use something cold to apply to the tap? Like a can of air turned upside down? That may give you some slight metal contraction, but it may be just enough to loosen the tap enough to get it going? Not sure if that's allowed.

If you have some really small Allen wrenches (or something similar) that can fit into the spaces, you could try inserting them, then gripping them with some locking pliers and twist.

 

[Beowulf]

 

[2ndGearRubber]

I know NOTHING about what is or isn't allowed.

How deep is it? Can you insert a steel/aluminum tube down the hole to protect the threads, then weld to the tap to either build up something to grab onto, or eventually weld a nut to it?

Try an Allen key as a punch, like a 1mm key or less, and try to knock on the tap to wiggle it. Actually sticking two Allen keys down then connecting them with locking pliers or a welder may produce a tap removal tool.

I wouldn't be afraid of taking a pair of very small electronics style needle nose, and grinding the tips down until they can fit within the tap flutes, again as a ghetto extractor.

I would also consider if you can hit it with a left handed bit. Center punch a hole, then low rpm infinite down force and try to get the drill to bite and jerk the tap.

 

[Walkers]

A valve core remover might work

 

[manwithtools]

I know NOTHING about what is or isn't allowed.

How deep is it? Can you insert a steel/aluminum tube down the hole to protect the threads, then weld to the tap to either build up something to grab onto, or eventually weld a nut to it?

Try an Allen key as a punch, like a 1mm key or less, and try to knock on the tap to wiggle it. Actually sticking two Allen keys down then connecting them with locking pliers or a welder may produce a tap removal tool.

I wouldn't be afraid of taking a pair of very small electronics style needle nose, and grinding the tips down until they can fit within the tap flutes, again as a ghetto extractor.

I would also consider if you can hit it with a left handed bit. Center punch a hole, then low rpm infinite down force and try to get the drill to bite and jerk the tap.

All good ideas, but did you see how small this tap is? Gonna be hard to center punch and left hand drill or weld or...

 

[Beowulf]

A valve core remover might work

Honestly that might work, but could still be too big. I have one at home, I'll check.

 

[slowtwitch73]

Do you have the other half?

Some *carefully* applied CA glue might be the hail mary you are after.

 

[jayemm]

Do you have the other half?

Some *carefully* applied CA glue might be the hail mary you are after.

I could see CA (cyanacrolate Crazy Glue) glue hindering a clean removal by gumming things up further. Besides, CA glue has poor torsional shear strength, where torque/shear force is involved in this application which requires turning.

 

[Toold_up]

I would also consider if you can hit it with a left handed bit. Center punch a hole, then low rpm infinite down force and try to get the drill to bite and jerk the tap.

Squirt some lube in the hole and left hand it.

Do you have the other half?

Some *carefully* applied CA glue might be the hail mary you are after.

Good adhesive can be just as strong as a weld at that small of a diameter.




You might be able to squirt some lube into the hole, then fill it with epoxy + a handle of some sort. Wait for the epoxy to harden and just unscrew it.

 

[dnschmidt]

Liquid nitrogen. Go to any dermatologist as they have this in what looks like an insulated oil squirt can. Make him an offer he can't refuse, like a Benjamin or two. My dermatologist squirts liquid nitrogen on my head every time I see him. It kills pre-cancers.

 

[Toold_up]

You could also grind a slot at the tip of a punch that will fit into the flutes of your tap and unscrew it. Be careful you don't wind up with a bouquet of ********.


Or take it to a machine shop and have them take a crack at it.

 

[dnschmidt]

You can't drill a tap. Taps are twenty times harder than any drill bit. Unlikely that even solid carbide would work.

 

[Toold_up]

You can't drill a tap. Taps are twenty times harder than any drill bit. Unlikely that even solid carbide would work.

Sure It depends on the tap, but we aren't talking about drilling through it. The left hand drill bit will try to dig in and bite whatever it can, and since it's spinning in reverse it will naturally back it out. If he can wiggle the tap, I'm betting a left hander will work. Just be sure to use lube...

 

[Tactile]

You could also grind a slot at the tip of a punch that will fit into the flutes of your tap and unscrew it.

This. Or butcher a appropriately sized drill bit. Anyone there handy with a Dremel?

 

[dogdog]

OMEGADRILL OD-5/64 5/64

Machine Shop SolutionsProblem: Extracting broken taps is as frustrating as it is time-consuming. Solution: OmegaDrill Tap Extractors remove broken taps quickly and easily, and substantially reduce downtime!Remove The Frustration Of Broken Taps With OmegaDrillStop scrapping expensive parts and...

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I remember seeing this while browsing, don't know how it works.

 

[KnurledNut]

Im thinking some offering suggestions dont realize how small this tap is.

 

[ItsNemo]

You can't drill a tap. Taps are twenty times harder than any drill bit. Unlikely that even solid carbide would work.

Most taps are high speed steel, carbide will cut high speed steel.

 

[2ndGearRubber]

All good ideas, but did you see how small this tap is? Gonna be hard to center punch and left hand drill or weld or...

2mm hole about? If it's not deep you could MIG that. Honestly just stuff that ***** in there and fry it the best you can.

I figured if they're doing stuff that small they'd have the tiny bits required. You're talking a 3/64 bit. I think you'd probably just use number/letter bits. IDK what aerospace people do or don't have.

If they have a rigid enough setup, you could hog it out with carbide. But I wouldn't try to freehand that.

 

[2ndGearRubber]

Most taps are high speed steel, carbide will cut high speed steel.

You hardly even need to bother really cutting into it. Even if it and the bit instantly work harden, you really just need one sweep to try and jerk the tab free of what is likely a nasty hang-nail in the threads.

This goes into copper, at what point can we use an m5 or m6 thread insert? Cut deep enough to deal with the tap, cut to m6 or whatever. Insert stud with locktite, cut flush. Retap original hole in locktited fastener secured into parent material. Works good on timing covers and heads people severely miss-drill. But my stuff doesn't go to space.

 

[GMSF]

If you can wiggle it with tweezers but it’s too jammed to turn out keep some left hand tension on the tap and LIGHTLY vibrate the piece with an air hammer (if there is a safe place). A sawzall with no blade pushed against the piece can vibrate it as well. Do this upside down if possible.

 

[ZRX61]

If you can wiggle it with tweezers but it’s too jammed to turn out keep some left hand tension on the tap and LIGHTLY vibrate the piece with an air hammer (if there is a safe place). A sawzall with no blade pushed against the piece can vibrate it as well. Do this upside down if possible.

Given the size of the hole, a ***** would be a better choice than an air hammer or sawzall.

 

[KnurledNut]

2mm hole about? If it's not deep you could MIG that. Honestly just stuff that ***** in there and fry it the best you can.

I figured if they're doing stuff that small they'd have the tiny bits required. You're talking a 3/64 bit. I think you'd probably just use number/letter bits. IDK what aerospace people do or don't have.

If they have a rigid enough setup, you could hog it out with carbide. But I wouldn't try to freehand that.

Bro, this is a spaceship, not a Silverado. They cant bring it back during lunch tomorrow because the bolt fell out.

 

[Toold_up]

Whatever you decide make sure you take your time and think it through.

 

[2ndGearRubber]

Bro, this is a spaceship, not a Silverado. They cant bring it back during lunch tomorrow because the bolt fell out.

I got pretty high in my late teens, but I already said I don't build spacecraft.


I would believe any suggestion would be vetted against what is acceptable risk by the parties involved.. This part is junk, currently. We can either build a new one, or attempt to remove/repair with a variety of suggestions offered.

IMO the tap probably broke because it got bottomed out. HSS should never be losing against copper, unless this is some secret military copper I'm not aware of. Not sure how else it would have gotten broken. OP needs a plethora of suggestions, so no option is unturned. It's think of every possible avenue to repair, or build a new one.

Some electronics screwdrivers, like 000 size, could be thinned out with a die grinder to create a pair of flutes to try and grab/push against either side.

 

[GMSF]

Given the size of the hole, a ***** would be a better choice than an air hammer or sawzall.

Hah, that’s fair. I suppose it comes down to the size of the piece the hole is in, but yes those might be a little much. For something very small and delicate, maybe an electric engraver pen would be more appropriate.

 

[JABgj]

How about snap ring pliers? Little ones.

 

[Muckin_Slusher]

IMO the tap probably broke because it got bottomed out. HSS should never be losing against copper, unless this is some secret military copper I'm not aware of.

This comment makes me think you're not as smart as you think you are.

Copper is funny and gummy and can be difficult to drill (with regular twist drill bits).

There is a hell of a lot more mass to the copper than there is in that dinky HSS tap. Steel might be stronger than copper, but a copper sledge can still put a hell of a dent in a steel car hood.

 

[teagueo]

Let us know what your solution ends up being.

Sounds like you're saying the part is scrapped unless the tap can be coerced out?

Or can you go through the lengthy disassembly process and EDM the component away from the more delicate hardware? Surely, taking the time to custom machine a 2 flute removal tool would be better than risking anything else and shouldn't take long.

 

[slowtwitch73]

I could see CA (cyanacrolate Crazy Glue) glue hindering a clean removal by gumming things up further. Besides, CA glue has poor torsional shear strength, where torque/shear force is involved in this application which requires turning.

That's why you have to carefully apply. If the break is jagged (good) the break itself would be taking the force, the CA just keeping it together to do so.

CA glue is also easily dissolved with acetone.

 

[2ndGearRubber]

This comment makes me think you're not as smart as you think you are.

Copper is funny and gummy and can be difficult to drill (with regular twist drill bits).

There is a hell of a lot more mass to the copper than there is in that dinky HSS tap. Steel might be stronger than copper, but a copper sledge can still put a hell of a dent in a steel car hood.

IDK how smart I am, but I've drilled out copper. It wants to grab/bind, so you can't let it self feed. Step bits hog it out pretty easily, again, so long as it doesn't self feed. How copper drills is entirely irrelevant, we're not drilling.

They were cleaning threads per the OP. So unless the threads were completely rolled over, the tap should completely dominate the copper. I see something orange/copper in the bottom of the hole. I'm ASSuming it's a blind hole as a result. Do you have a better explanation of how a hole with already cut threads managed to grab and snap a tap of the same size? I can see a dull tap pulling/tearing instead of cutting cleanly. But I have my doubt areospace people use dull taps, IDK, never been to space.