Removing a broken tap from a bolt hole

[woodstalker]

Had to remove the glass balustrade from the roof terrace because there was a leak. Utterly dreadful installation and I have temporarily patched it until the better weather next year when I will repair the roof and reinstall the balustrade myself (got quoted £12k to remove balustrade, repair roof, reinstall balustrade!)

Can anyone suggest the best way to get the two broken off taps in the bolt holes? I thought I could drill them out but the steel is very strong and brittle…

 

[Malc2098]

How about welding the end of a rod to it at an angle and then using the rod to unscrew it?

 

[Dr.Al]

View attachment 29422

Had to remove the glass balustrade from the roof terrace because there was a leak. Utterly dreadful installation and I have temporarily patched it until the better weather next year when I will repair the roof and reinstall the balustrade myself (got quoted £12k to remove balustrade, repair roof, reinstall balustrade!)

Can anyone suggest the best way to get the two broken off taps in the bolt holes? I thought I could drill them out but the steel is very strong and brittle…

Ooh, that's going to be a horrible job. The tap is probably high-speed steel. You might be able to drill it with a carbide drill bit but you'll need the drill to be held very stable for a good result and that is likely to be a challenge. If it's a carbon steel (not high-speed steel) tap (which you might know if you bought the tap) then heating it up with a narrow flame from a blowtorch and allowing to cool slowly might soften it and that would make it easier to remove. It's also possible with high-speed steel but needs a heck of a lot more heat.

If you've got access to a TIG welder, then welding something onto the exposed end of the tap might also be an option, but it's a difficult weld to do and if you don't have a TIG welder then it's an even more difficult weld to do. The industrial way of doing it would be spark erosion, but that's not that easy if you don't have a spark eroder!

What material (and thickness) is the surface that the tap is stuck in? It's hard to tell from the picture. That could also make a difference to the available options.

If it's a plausible option then my favourite would probably be to get a small hole saw or annular cutter (the smallest one you can find) and drill around the tap so you're removing the material that the tap is stuck in rather than the tap itself. Again that'll need a fairly stable set-up as the hole saw won't have a central pilot drill to keep it in-line. Once the tap (and the material around it) has been removed, then fill the hole with something (either by welding, brazing, gluing, patching or some other method).

 

[AJB Temple]

It looks like there might be just about enough room to drive some steel rods or nails down the clearways in the tap and grip them very tight with mole grips and unscrew it. I would get some lubrication down there before trying to unscrew. This is the least work option and worth a try.

 

[wallace]

I've managed to remove broken taps with long nose pliers, it trashes them but sometimes works

 

[woodstalker]

Here is the second tap snapped off from underneath. The holes are in a steel I Beam under a GRP flat roof.

I have a mig welder with flux core wire but that’s it sadly.

I cold really do with removing the taps and threading the holes to allow them to be used.

It’s a tough one but I know you guys are good at tough problems.

 

[Dr.Al]

How thick is the steel?

 

[woodstalker]

How thick is the steel?

Hi Dr Al, I’m not sure. It’s got reinforcing flat bar filter to the top and bottom; a few mm but tricky to measure because it’s encased in the roof structure currently. I’ll dig out the structural engineers spec and see what they say

 

[Trevanion]

You can always smash a tap through with a punch but it will mangle the threads, but frankly any option will likely mangle the threads without a very careful and sturdy setup like boring the tap out in a mill with a carbide drill, which isn't possible in this setting obviously.

Have the taps recently been broken in the holes or have they been there a long time? I have had success in the past using a punch at an angle in a counter-clockwise fashion to reverse the tap out of a hole but I don't think you'll have much luck in a rusty hole.

 

[toolsntat]

There are extractors for this but time may be a critical factor for your examples in, as mentioned above, them now being rusted ?
This sort of thing.....

Broken Tap Extractor (Single Sizes) - 3mm to 30mm

Broken Tap Remover Tools Single Sizes We stock 14 sizes 3mm to 30mm (1/8 to 1.1/4") Removes broken / damaged taps with ease How to work out which size you require *what size is broken Tap *check the number of flutes on broken Tap 3 or 4 * go to list to suit your requirement. How To Use Try...

www.lprtoolmakers.com.au

Cheers, Andy

 

[woodstalker]

Yes the ‘installation’ was in April 2022 but all this was hidden until I opened it all up to locate the leak.

I will give your suggestions a go but I suspect I’ll have to try and cut them out, weld in steel to fill the mess created and then re drill & tap them. Very frustrating. Cheers all as ever!

 

[9fingers]

Flood with plus gas and unscrew the tap from the bottom up. Gentle forward and back until it starts to move. Do not force it

 

[DaveL]

Instead of WD40, try to get some Plusgas, it is a much better penetrating fluid.
When I used rebuild old British bikes, I bought it by the gallon.

 

[woodstalker]

Thanks guys I have some plus gas, will add it to my just if options.