rounded allen bolt on door check strap
tried drilling through it but its not going anywhere

thought of this, but guy at shop said its only for normal bolts

what to do

Try and get a small cold chisel and knock it round using that and a hammer as drilling it you would be there all day!

Get a chiesel and hit it hard into the Nut that remains to make a Slot, so hopefully a screwdriver can get it to spin out

However - a V groove nocked into 1 side of a rounded bolt and then tapped with a punch often works very well as there is alot of impacting which makes it loosen

You find alot of mechanics will often do this method when a brake disc retainer screw cheeses up and then wont come out

Ziggy

Cheap and nasty easy outs usually snap. And you need a carbide drill to drill the hole.

How did you manage to make such a pig's ear out of it?

Normally I just weld a nut on, but if you've not got a welder, that's not really an option.

v grove sounds good
got a welding machine but havent welded anything in years

fingers99 said:

Cheap and nasty easy outs usually snap. And you need a carbide drill to drill the hole.

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Too right about those cheapo extractors, total waste of money. It's hit and miss even with a good one.


Grind a slot with a dremel for a screwdriver

I also quite like left hand drill bits, but maybe not on this job...

Fist like to use a lot of stainless bolts on the punto (as I discovered recently) nothing but a good quality cobalt drill bit will go through it.

As you drill into stainless steel it tempers and hardens with the heat so it drills nicely to start with then it's like hitting a wall and will happily eat bit after bit if you're just using standard hss bits

You could weld things or mess about with chisels but you will damage the paint or body work and probably end up with rust setting in fast soon after

The reason the bolt wouldn't budge is because the steel and stainless steel react and stick to each other almost weld themselves together.

When drilling always use plenty of coolant gt85 spray is good

AndyRKett said:

The reason the bolt wouldn't budge is because the steel and stainless steel react and stick to each other almost weld themselves together.

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So does ordinary steel. Cold welds occur under pressure in torqued threads in most materials. This is why copper grease is your best friend.

Sharp (but not overly forceful) taps with a hammer are a good way to break them before trying to remove a stubborn bolt. In this case, I'll back the previous suggestions of knocking it anti-clockwise with a cold chisel. Carefully. Drilling it will be a giant pain in the backside.

Monkeh16 said:

So does ordinary steel. Cold welds occur under pressure in torqued threads in most materials. This is why copper grease is your best friend.

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Cold welds occur overtime when identical metals left in contact corrode together and bond this isn't the same as actual welding which is why a tap with a hammer will break the bond and allow the easy removal of the nut/bolt

Carbon steel mixed with stainless steel will in the presents of an electrical current undergo a galvanic reaction which actively welds the components together, add to this the softer nature of stainless steel and no amount of tapping with a hammer will release the bond

In this case the Allen bolt has a nice centered hole in the head to start off the drilling, as mentioned a cobalt drill bit will eat through it in 30 seconds and a tap and die set can be bought for £10-20 which can be run through to clean up the threads of the hole after

Trying to chisel it out will just result in knocking bits of the bolt off and risk damaging the door and area around from slipping with the chisel

I have very recently had to do exactly the same thing so I know this is not just the quickest but actually the only way to do this job on a Punto

AndyRKett said:

Cold welds occur overtime when identical metals left in contact corrode together and bond this isn't the same as actual welding which is why a tap with a hammer will break the bond and allow the easy removal of the nut/bolt

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Actually, no, cold welds exclude corrosion. You can get corrosion holding two parts together, but that is not cold welding.

If you bring two identical materials together with no contamination (surface contaminants, corrosion, air.. all these get excluded when torquing a bolt), they actually bond. This is a cold weld. It is how crimp connectors work, and why spade connectors get stuck.

You're mostly right about stainless, though, galvanic corrosion is a problem. It's not welding or cold welding, though..

got it out finally

An impact driver may help in shifting this, cut a slot with a Dremel as suggested in an earlier post, then use the impact driver. The sudden jolt often helps loosen a seized fastener.

flisko said:

got it out finally

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Tapped it round?

Weld a bolt on and undo

Monkeh16 said:

Tapped it round?

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hammer+screwdriver