What are the chances of getting this tap out? (pic)

[nateman_doo]

All this started because the ballscrews I ordered from China were the wrong effing size. I could strangle him right now because he sent the wrong size sent me down this debacle to try and extend my table.

In any case, what are the chances that I can get this sucker out? its 1/2" and I don't have many capabilities at my disposal.

I really could choke him right now, but whatever its done. I send him an e-mail demanding the correct sizes. Bad enough I will ship these longer ones back to china, and I am not going to pay someone additional money to turn them and make shorter. Thats more money out of my pocket because he couldn't read a drawing, or he was rushing the job.

[nateman_doo]

I was extending the table to accommodate the longer screw. I had the surface mated with a 1-2-3 block to ensure it was on the same plane.

I drilled the hole with a hand drill so it was oversized. The tap had to be pretty crappy to begin with because I wasn't using much torque to begin with.

Here it was aligned with a punch where I marked the holes.

[Geof]

That is a challenge. Can you get the table off so you can stand it on end? If this is possible you can try strong sulphuric acid to (slowly) dissolve the tap. Provided it is not really concentrated it will not attack the aluminum.

This will take time and you may need to suck out the depleted acid and replenish but this would be possible with a syringe.

Needless to say you need protective equipment such as eye proection and gloves; maybe even a face shield so you cannot splash yourself in the face. And old clothes.

The only other possibility I can think of is trying to build up the end of the tap with stainless weld but you need a stick welder for this and you need a bit of skill in welding.

I suppose I shouldn't have said the only other thing because of course you could try to find someone with and EDM machine.

Then I Googled 'tap blaster EDM' and found this:

How-To Remove Broken Taps, or Making and Using a Basic EDM

So maybe all is not lost.

Now for a gentle rap over the knuckles. You were using a spiral flute tap for hand tapping. Not a good idea, they can handle the load of a nice straight torque which is what they experience in a machine, but they do not like any side load and it is virtually impossible to hand tap without pulling sideways a little bit on the tap. They also do not have much taper on the end so they cut a full thread within a couple of turns which increases the load on the tap.

For hand tapping what you need is a taper hand tap which gets the thread started easily then you follow this with a bottoming tap to get a full thread form as deep as you need.

[scudzuki]

Spiral flute tap removal is a bit more difficult than say a gun tap with one of these but I have done it.
McMaster-Carr

Joe

[SCzEngrgGroup]

By far the best taps for hand-tapping are spiral-point, NOT spiral-flute, taps. They cut FAR easier than conventional hand taps, and don't load up, since they push the chips ahead of the tap, instead of forcing them up the flutes. They require care to do blind holes, but they are the only taps I'll use anymore.

Regards,
Ray L.

[chipslinger69]

I have been in the same boat before. I used a set of needle nose pliers stuck in between the flutes and worked it back and forth until it finally came out. I am not sure how you were using it but when I hand tap a hole I go in 1 full turn and back it out 1/2 a turn that way I don't load up the flutes and bind the tap causing it to break. Sometimes on blind holes I even pull the tap completely out after every full turn just to clean the cuttings out of the hole.

[FannBlade]

Needle nose pliers like he said with little heat on surrounding aluminum that should hopefully gain some movement so you can work it back and forth then start add cutting fluid to free it even more,,,cuss,swear,pray and repeat. Always think about how it will work using 5/8" when that hole is beyond use ...or patience.

[nateman_doo]

All it took was needle nose pliers and a good night sleep. It was a 1/2" tap so there was meat on the tap to grab. I was so in shock that it broke on the way out. Spiral point taps are much better, but this was the only 1/2" tap I had.

[hoss2006]

Spiral point or gun taps are for power tapping thru holes as they push a chip curl ahead of the tap.
Using one for a blind hole just packs the chips into the bottom of the hole,
A spiral flute can be used manually or powered and pulls long curled chips out of the hole
just like a drill bit and allows the hole to be tapped in one shot.
A straight flute plug tap is one that has a tapered point that aides in aligning and starting the tap into an untapped hole.
By hand you continually peck your way into the hole and clear the small chips that the oil
helps cling to the flutes.
If it's a blind hole, finish with a bottom tap pecking the same way.
Irregardless, dull taps used without enough oil will snap on occasion.
Hoss

[LUCKY13]

All it took was needle nose pliers and a good night sleep. It was a 1/2" tap so there was meat on the tap to grab. I was so in shock that it broke on the way out. Spiral point taps are much better, but this was the only 1/2" tap I had.

If it broke on the way out its becuase you didnt back it up and clear/break the chips enough. This is why you have to turn in a little, then back it out. If you dont do it enough the chip gets to big and ofcourse as you felt it binds the tap and snap.



Atleast you got it out, it feels bad when they break on you.


Jess

[loply]

Looking at that I think you could make an extractor tool to unscrew it.

Get a piece of hard rod (drill rod?) which is the same size as the hole.

Carefully punch three holes in the end of the rod and tap them and insert three small threaded rods in a triangular layout into the end of the drill rod.

Design it such that these three small studs will engage in the 3 empty spaces on the back of your tap.

The studs will therefore need to be around 2mm OD I guess, but can presumeably be 5-10mm long.

Once you have this tool simply insert it into the hole and unscrew the tap.

If you have the drill rod to-hand and some 2mm or 3mm bolts to use as your studs I guess this could be knocked up in 20 minutes?

Rich

[chipslinger69]

All it took was needle nose pliers and a good night sleep. It was a 1/2" tap so there was meat on the tap to grab. I was so in shock that it broke on the way out. Spiral point taps are much better, but this was the only 1/2" tap I had.

Needle nose pliers are life savers.