Drilling Out Bolt

[2052006 10]

Tried to undo the earthing bolt behind the washer fluid bottle - on the n/s/f wing - and the head sheared off. Fine I thought, I'll drill the rest out. But no, my drill bits are hardly making any progress. What on earth is this stupid bolt made out of?! Are there special bits you can use for this sort of thing?

[GTI6BOY 29]

a very good drill bit is needed and set the drill to the lowest speed

[Henry 1.9GTi 36]

had same problem, knackered 3 drill bits trying to get it out, in then end I gave up and moved the earth

[Alan_M 66 1 Cars]

Are your drill bits in good condition to start with?

 

Most of the drill bits available in your B&Q or Halfords are pants IMO, I bit the bullet and bought myself a set of Dormer bits instead.

 

Try using a pilot drill first, building up in bit size to the OD of the bolt using a slow speed as someone above said.

[Tom Fenton 1,548]

Agreed, get yourself some decent drills and you will have no problem.

[2052006 10]

So crap drill bits it is then - I have some black and decker/pirahna ones from Homebase. Are dewalt ones any better? Or can anyone recommend some decent makes and where to get them?

 

Thanks

 

P.S. I realise I could move the earth, but I am determined to get this ****** out now

[maturin23 10]

I remember spending two hours and at least 4 drill bits trying to drill out a bolt - was trying to remove a winch on a 130ft sailboat I was working on.

 

There were two bolts that needed drilling, first one came out fairly easily. I then had some lunch and went back to the job.

The second one just wasn't having any of it. Only after two hours and two trips to the chandlery for another drill bit did I realise that the drill was spinning in the wrong direction

 

Someone had borrowed the drill at lunch, used it to get some screws out and not reset the direction.

 

In my defence was 15 years ago and I'd never used a cordless drill before with a reverse gear, also it was in 100F heat in Mexico

 

I still get grief about this from my pal who was skippering the boat at the time.

[Cloverleaf 1]

If you really are determined (££) get some carbide drill bits

 

http://uk.rs-online.com/web/search/searchB...55621&Nty=1

[large 33]

You could use a masonry bit. Do this in work from time to time when we have a very hard bolt. I would have thought that a good set of drills will sort you out.

[hispetdog 0]

non cheesey drill bits, some cutting fluid and set your drill at HIGH speed let it cut! should be no prob.

[Tom Fenton 1,548]

Disagree. All high speed will achieve is heating the material you are drilling, this will then cause the carbon to come to the surface making it rock hard meaning you will never drill it.

[j_turnell 137 3 Cars]

As above i've always found it much more effective to drill on a slow speed, rather than a high speed.

[welshpug 1,666]

Disagree. All high speed will achieve is heating the material you are drilling, this will then cause the carbon to come to the surface making it rock hard meaning you will never drill it.

 

 

I always wondered what the explanation was to what happened when you tried a blunt drillbit then used a new bit which went blunt straight away, makes sense now

[Tom Fenton 1,548]

It is also the reason that you should never heat anything up if you want to drill it.

[2052006 10]

That'll be why it's so rock hard then - I tried it on high speed at first. So does this make it impossible to get out? Thanks for the info though - learn something new everyday. Albeit too late

 

I have a mate coming over tomorrow to (with any luck) reangle my manifold for my gti6 engine. We'll have a go at the bolt too.

[dicky20014 4]

Other options (may not be feasable/bolt to tight).....

 

1. Borrow a set of stud removers, drill a pilot hole and use the stud extracter to remove it

2. If you cant get some stud extracters, hammer a (old) allen key into the pilot hole and try to turn that

3. Cut a 'slot' with a hacksaw in the top of the stud and use a screwdriver to try and get it out

4. mole grips

 

Rich

[hispetdog 0]

if you have drill bits made of toffee then yeah low speed might be better but a gd drill bit, high speed and cutting fluid works a treat. when I needed to drill a 12.9 bolt that worked well and they r as hard as a whores heart! lol

[large 33]

It all depends on what size bit you are useing all drill bits have a optimum speed. The smaller the bit the faster you can run.

[Tom Fenton 1,548]

if you have drill bits made of toffee then yeah low speed might be better but a gd drill bit, high speed and cutting fluid works a treat. when I needed to drill a 12.9 bolt that worked well and they r as hard as a whores heart! lol

 

As any engineering apprentice will tell you, any size of drill has an appropriate peripheral speed suitable for drilling materials. "Flat out and cutting fluid" is not the corect way of drilling anything.

[hispetdog 0]

Sorry. I was assuming the bolt wasn't bigger than 6mm.

Edited May 7, 2009 by hispetdog

[fast_eddie 0]

Just re wound my garage door up and over spring after the locking screw gave way. Luckily there was no one underneath it at the time when it went!!

Anyway, I wound the spring back to a similar position and then drilled through the tension boss and right through the stainless (10mm) shaft. Slow and steady with plenty of wd40 as a cutting/cooling fluid. Once I had found a sharpened drill bit it was all ok from there.

Listen and feel the drill bit you are using, you can tell just before the bit breaks through the hole as it kind of slows a little---note to self, back off trigger before drill bit snaps!!