Having to remove the ends of some sheared off bolts in
cast iron, I wonder what's the best way (preserving the
threads in the hole as much as possible) to do this.

I ran some 2mm drills down the threads, one on each side,
then a larger hole down the middle to join, as near as
possible, the two smaller ones:

,-.
' '
o O o - holes drilled down each
` ' side of bolt/threaded hole
`-'

Apologies for the dodgy ASCII art. The bits of bolt left
in the hole could then be worked out, leaving usable
threads.

Is there a better way, using a hand-held electric drill?

Spark erosion might be another way (but not exactly
"portable") - other ideas?

Chris Bacon wrote:
Having to remove the ends of some sheared off bolts in
cast iron, I wonder what's the best way (preserving the
threads in the hole as much as possible) to do this.

I ran some 2mm drills down the threads, one on each side,
then a larger hole down the middle to join, as near as
possible, the two smaller ones:

,-.
' '
o O o - holes drilled down each
` ' side of bolt/threaded hole
`-'

Apologies for the dodgy ASCII art. The bits of bolt left
in the hole could then be worked out, leaving usable
threads.

Is there a better way, using a hand-held electric drill?

Spark erosion might be another way (but not exactly
"portable") - other ideas?



I usually drill a 3mm hole hown the middle, then enlarge it to say
5-6mm, then tap in a screwdriver. Works most of the time.


--
Grunff

"Chris Bacon" wrote in message
...
Having to remove the ends of some sheared off bolts in
cast iron, I wonder what's the best way (preserving the
threads in the hole as much as possible) to do this.

I ran some 2mm drills down the threads, one on each side,
then a larger hole down the middle to join, as near as
possible, the two smaller ones:

,-.
' '
o O o - holes drilled down each
` ' side of bolt/threaded hole
`-'

Apologies for the dodgy ASCII art. The bits of bolt left
in the hole could then be worked out, leaving usable
threads.

Is there a better way, using a hand-held electric drill?

Spark erosion might be another way (but not exactly
"portable") - other ideas?

first off I try welding onto the broken bit and try molegrips on the
resulting lump, works about half the time.

Accurate drilling down the middle with progressively larger drills till the
threads can just be seen then remove the 'spring' that is left behind. If
you mess up the threads in there then get a stud and set it in place with
loctite and put a nut on it, that way you can screw right to the bottom of
the threads in the casting, often the end ones are still good. Or just put
a helicoil in.

mrcheerful

Chris Bacon wrote:
Having to remove the ends of some sheared off bolts in
cast iron, I wonder what's the best way (preserving the
threads in the hole as much as possible) to do this.

I ran some 2mm drills down the threads, one on each side,
then a larger hole down the middle to join, as near as
possible, the two smaller ones:

,-.
' '
o O o - holes drilled down each
` ' side of bolt/threaded hole
`-'

Apologies for the dodgy ASCII art. The bits of bolt left
in the hole could then be worked out, leaving usable
threads.

Is there a better way, using a hand-held electric drill?

Spark erosion might be another way (but not exactly
"portable") - other ideas?

drilling a decent side hole of good depth then using a tap&die set with a
anticlock wise thread, put in a bolt off the correct tap die and bingo! it
unscrews the old bolt/screw.
--
Sir Benjamin Middlethwaite

In message , Chris Bacon
writes
Having to remove the ends of some sheared off bolts in
cast iron, I wonder what's the best way (preserving the
threads in the hole as much as possible) to do this.

[..]

Is there a better way, using a hand-held electric drill?


1 - Easy Out
2 - Left handed drill bit

Hth
Someone

On Wed, 16 Nov 2005 12:45:13 +0000, Chris Bacon
wrote:

Having to remove the ends of some sheared off bolts in
cast iron, I wonder what's the best way (preserving the
threads in the hole as much as possible) to do this.

Go to Halfords and buy some of Facom's parallel pin bolt extractors.
You'll also need a good engineering toolshop and a good quality drill
bit of _exactly_ the right obscure diameter. Keep the drill(s) with the
extractors for this purpose alone.

These aren't the old "tapered screw wedge" extractors, they actually
work.


And the usual stuff about applying heat or real Plus-gas beforehand.
Even a dose of electrolytic de-rusting can be useful on cast iron.

The message
from somebody contains these words:

2 - Left handed drill bit

They're the dog's danglers if you can get 'em.

--
Skipweasel
Never knowingly understood. (Ivor Cutler)

Chris Bacon wrote:
Having to remove the ends of some sheared off bolts in
cast iron, I wonder what's the best way (preserving the
threads in the hole as much as possible) to do this.

Is there a better way, using a hand-held electric drill?

There used to be things of purpose called Easyouts. Don't know if they
are still available?

--
Holly, in France
Holiday Home in Dordogne
http://la-plaine.chez.tiscali.fr/

On Wed, 16 Nov 2005 13:08:07 GMT, "The3rd Earl Of Derby"
wrote:

drilling a decent side hole of good depth then using a tap&die set with a
anticlock wise thread, put in a bolt off the correct tap die and bingo! it
unscrews the old bolt/screw.

So that's using

a) an expensive left handed tap
b) an expensive left handed bolt

fx - falls off chair laughing


--

Matt wrote:
On Wed, 16 Nov 2005 13:08:07 GMT, "The3rd Earl Of Derby"
wrote:

drilling a decent side hole of good depth then using a tap&die set
with a anticlock wise thread, put in a bolt off the correct tap die
and bingo! it unscrews the old bolt/screw.

So that's using

a) an expensive left handed tap
b) an expensive left handed bolt

fx - falls off chair laughing

Never heard of second hand shops?
Erm! the dies that you bought from the secondhand shop create a lefthand
thread.

fx - falls off chair laughing



--
Sir Benjamin Middlethwaite

Andy Dingley wrote:
Chris Bacon wrote:
Having to remove the ends of some sheared off bolts in
cast iron, I wonder what's the best way (preserving the
threads in the hole as much as possible) to do this.

Go to Halfords and buy some of Facom's parallel pin bolt extractors.
You'll also need a good engineering toolshop and a good quality drill
bit of _exactly_ the right obscure diameter. Keep the drill(s) with the
extractors for this purpose alone.

Got an URL for this? I can't find them.

Chris Bacon wrote:
Andy Dingley wrote:
Chris Bacon wrote:
Having to remove the ends of some sheared off bolts in
cast iron, I wonder what's the best way (preserving the
threads in the hole as much as possible) to do this.

Go to Halfords and buy some of Facom's parallel pin bolt extractors.
You'll also need a good engineering toolshop and a good quality drill
bit of _exactly_ the right obscure diameter. Keep the drill(s) with
the extractors for this purpose alone.

Got an URL for this? I can't find them.

Use this instead.
http://www.machinemart.co.uk/product...0&r=2080&g=111
--
Sir Benjamin Middlethwaite

"Guy King" wrote in message
...
The message
from somebody contains these words:

2 - Left handed drill bit

They're the dog's danglers if you can get 'em.


Snap on sell them, not too dear either.

mrcheerful

"The3rd Earl Of Derby" wrote in message
k...
Chris Bacon wrote:
Andy Dingley wrote:
Chris Bacon wrote:
Having to remove the ends of some sheared off bolts in
cast iron, I wonder what's the best way (preserving the
threads in the hole as much as possible) to do this.

Go to Halfords and buy some of Facom's parallel pin bolt extractors.
You'll also need a good engineering toolshop and a good quality drill
bit of _exactly_ the right obscure diameter. Keep the drill(s) with
the extractors for this purpose alone.

Got an URL for this? I can't find them.

Use this instead.
http://www.machinemart.co.uk/product...0&r=2080&g=111
--
Sir Benjamin Middlethwaite


Those taper things are a waste of time unless the bolt is already loose, if
the bolt is tight then they spread out the remainder and ensure it never
comes out.

mrcheerful

The3rd Earl Of Derby wrote:
Chris Bacon wrote:
Andy Dingley wrote:
Chris Bacon wrote:
Having to remove the ends of some sheared off bolts in
cast iron, I wonder what's the best way (preserving the
threads in the hole as much as possible) to do this.

Facom's parallel pin bolt extractors..

Got an URL for this? I can't find them.

Use this instead.
http://www.machinemart.co.uk/product...0&r=2080&g=111

Um. They're worse than useless on anything that's really
seized, unfortunately.

"Chris Bacon" wrote in message
...
Andy Dingley wrote:
Chris Bacon wrote:
Having to remove the ends of some sheared off bolts in
cast iron, I wonder what's the best way (preserving the
threads in the hole as much as possible) to do this.

Go to Halfords and buy some of Facom's parallel pin bolt extractors.
You'll also need a good engineering toolshop and a good quality drill
bit of _exactly_ the right obscure diameter. Keep the drill(s) with the
extractors for this purpose alone.

Got an URL for this? I can't find them.

Again, look in snap on catalogue, they are a pin with tiny ridges along the
sides, you drive them into a predrilled hole and using a special nut thing
you turn the broken bit out, the advantage is that they don't spread the
stud out (making it tighter in the thread)

mrcheerful

"Chris Bacon" wrote in message
...
....
Is there a better way, using a hand-held electric drill?

Stud extractors, which come in various forms. Simplest is the Draper four
piece set. To use those, drill a hole down the centre of the bolt, insert
extractor and unscrew the stub of the bolt. It works about half the time.
You can also get heavy duty ones that use a 1/2" square drive to extract the
bolt, which tend to be more reliable, but you will probably only find those
at an automotive trade supplier.

Colin Bignell

The message
from "Holly, in France" contains these words:

There used to be things of purpose called Easyouts. Don't know if they
are still available?

They almost always snap off in the hole, leaving you worse off than you
were before 'cos there's now an over-hardened lump of metal in the
middle of the offending stump. Perhaps really good quality ones are
properly heat treated to make 'em tough instead of brittle.

--
Skipweasel
Never knowingly understood. (Ivor Cutler)

The message
from "The3rd Earl Of Derby" contains these words:

Use this instead.
http://www.machinemart.co.uk/product...0&r=2080&g=111

Unless the're really good ones, they just snap off 'cos the Chinese
don't understand proper case-hardening.

--
Skipweasel
Never knowingly understood. (Ivor Cutler)

Guy King wrote:
"The3rd Earl Of Derby" writes:
Use this instead.
http://www.machinemart.co.uk/product...0&r=2080&g=111

Unless the're really good ones, they just snap off 'cos the Chinese
don't understand proper case-hardening.

Good Lord, are they *really* case-hardened? I am surprised.

In article , nbkm57
@hotmail.com says...

"Chris Bacon" wrote in message
...
Having to remove the ends of some sheared off bolts in
cast iron, I wonder what's the best way (preserving the
threads in the hole as much as possible) to do this.

I ran some 2mm drills down the threads, one on each side,
then a larger hole down the middle to join, as near as
possible, the two smaller ones:

,-.
' '
o O o - holes drilled down each
` ' side of bolt/threaded hole
`-'

Apologies for the dodgy ASCII art. The bits of bolt left
in the hole could then be worked out, leaving usable
threads.

Is there a better way, using a hand-held electric drill?

Spark erosion might be another way (but not exactly
"portable") - other ideas?

first off I try welding onto the broken bit and try molegrips on the
resulting lump, works about half the time.

This is good because the heat helps loosen the bolt. If there's a bit
of the broken thread protruding I usually try to weld a nut to it.

Accurate drilling down the middle with progressively larger drills till the
threads can just be seen then remove the 'spring' that is left behind.

Even if you only manage to clear the first few threads you can often use
a plug tap of the appropriate size to clean out the rest (but don't try
it if you can't get it started cleanly).

If
you mess up the threads in there then get a stud and set it in place with
loctite and put a nut on it, that way you can screw right to the bottom of
the threads in the casting, often the end ones are still good.

But beware of punching through the bottom of the hole.

Or just put a helicoil in.

I'd rather use an oversize bolt if possible - helicoils have an annoying
habit of coming out when you undo the bolt.

"Andy Dingley" wrote in message
...
On Wed, 16 Nov 2005 15:06:23 +0100, "Holly, in France"
wrote:

There used to be things of purpose called Easyouts. Don't know if they
are still available?

Those things (Lord Stanley just posted a link) are great if you have a
loose bush in a hole and you need to lock it permanently in place.
They're tapered and so they act to jam the thing you're trying to remove
even more firmly into the hole!

The good ones (Facom or Snap-on) are a parallel splined pin with a
"driver" nut that fits accurately over them. They're a bit fragile, but
they work very well without the wedging problem.
I have used these on a Exhaust stud on a car and it was so easy apart from
drilling the hole

In article ,
The3rd Earl Of Derby wrote:
Use this instead.
http://www.machinemart.co.uk/product...0&r=2080&g=111

Trouble with these is they often break and then you can't drill the
hardened steel out. If buying easy outs go to a good quality tool shop or
engineer's suppliers. And pay for the best.

--
*Confession is good for the soul, but bad for your career.

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
mrcheerful
. wrote:
Those taper things are a waste of time unless the bolt is already loose,
if the bolt is tight then they spread out the remainder and ensure it
never comes out.

And then snap off. ;-)

The parallel sided ones are much better.

--
*Arkansas State Motto: Don't Ask, Don't Tell, Don't Laugh.

Dave Plowman London SW
To e-mail, change noise into sound.

On Wed, 16 Nov 2005 14:12:44 GMT, "The3rd Earl Of Derby"
wrote:

Matt wrote:
On Wed, 16 Nov 2005 13:08:07 GMT, "The3rd Earl Of Derby"
wrote:

drilling a decent side hole of good depth then using a tap&die set
with a anticlock wise thread, put in a bolt off the correct tap die
and bingo! it unscrews the old bolt/screw.

So that's using

a) an expensive left handed tap
b) an expensive left handed bolt

fx - falls off chair laughing

Never heard of second hand shops?

Yes

Erm! the dies that you bought from the secondhand shop create a lefthand
thread.

No, with the notable exception of one supplier (Tracy Tools) I can
honestly say that I've NEVER seen a single left handed tap or die, let
alone a set of them for sale in any secondhand tool shop (and I have
frequented many over the years)


--

On Wed, 16 Nov 2005 14:02:35 GMT, Guy King
wrote:

The message
from somebody contains these words:

2 - Left handed drill bit

They're the dog's danglers if you can get 'em.

Can't agree with that! unless they "snag" during drilling all they do
is drill out the hole and exert no force in line with the thread
helix. They are usually just an expensive waste of time - I've got
quite a few but they hardly ever get used!
--

Matt wrote:
On Wed, 16 Nov 2005 14:12:44 GMT, "The3rd Earl Of Derby"
wrote:

Matt wrote:
On Wed, 16 Nov 2005 13:08:07 GMT, "The3rd Earl Of Derby"
wrote:

drilling a decent side hole of good depth then using a tap&die set
with a anticlock wise thread, put in a bolt off the correct tap die
and bingo! it unscrews the old bolt/screw.

So that's using

a) an expensive left handed tap
b) an expensive left handed bolt

fx - falls off chair laughing

Never heard of second hand shops?

Yes

Erm! the dies that you bought from the secondhand shop create a
lefthand thread.

No, with the notable exception of one supplier (Tracy Tools) I can
honestly say that I've NEVER seen a single left handed tap or die, let
alone a set of them for sale in any secondhand tool shop (and I have
frequented many over the years)

You must be unlucky then (Willdridges second hand shop, west derby road,
Liverpool, merseyside).

If you want new try RS components.

--
Sir Benjamin Middlethwaite

On Wed, 16 Nov 2005 17:00:50 -0000, Matt
wrote:

On Wed, 16 Nov 2005 14:12:44 GMT, "The3rd Earl Of Derby"
wrote:

Matt wrote:
On Wed, 16 Nov 2005 13:08:07 GMT, "The3rd Earl Of Derby"
wrote:

drilling a decent side hole of good depth then using a tap&die set
with a anticlock wise thread, put in a bolt off the correct tap die
and bingo! it unscrews the old bolt/screw.

So that's using

a) an expensive left handed tap
b) an expensive left handed bolt

fx - falls off chair laughing

Never heard of second hand shops?

Yes

Erm! the dies that you bought from the secondhand shop create a lefthand
thread.

No, with the notable exception of one supplier (Tracy Tools) I can
honestly say that I've NEVER seen a single left handed tap or die, let
alone a set of them for sale in any secondhand tool shop (and I have
frequented many over the years)



Left handed drill bits are fairly common & achieve the same result.

On Wed, 16 Nov 2005 12:45:13 -0000, Chris Bacon
wrote:

Having to remove the ends of some sheared off bolts in
cast iron, I wonder what's the best way (preserving the
threads in the hole as much as possible) to do this.

I ran some 2mm drills down the threads, one on each side,
then a larger hole down the middle to join, as near as
possible, the two smaller ones:

,-.
' '
o O o - holes drilled down each
` ' side of bolt/threaded hole
`-'

Apologies for the dodgy ASCII art. The bits of bolt left
in the hole could then be worked out, leaving usable
threads.

Is there a better way, using a hand-held electric drill?

Spark erosion might be another way (but not exactly
"portable") - other ideas?

Start with a centre drill, then continue with left hand spiral drill bits

The message
from Chris Bacon contains these words:

Use this instead.
http://www.machinemart.co.uk/product...0&r=2080&g=111

Unless the're really good ones, they just snap off 'cos the Chinese
don't understand proper case-hardening.

Good Lord, are they *really* case-hardened? I am surprised.

Properly done, case hardening would be ideal for this application. Leave
the metal tough enough not to snap but with a very hard skin so there's
plenty of bite into the victim.

--
Skipweasel
Never knowingly understood. (Ivor Cutler)

On Wed, 16 Nov 2005 17:19:31 GMT, "The3rd Earl Of Derby"
wrote:

Matt wrote:

No, with the notable exception of one supplier (Tracy Tools) I can
honestly say that I've NEVER seen a single left handed tap or die, let
alone a set of them for sale in any secondhand tool shop (and I have
frequented many over the years)

You must be unlucky then (Willdridges second hand shop, west derby road,
Liverpool, merseyside).

Not been over that way for years, but if I'm in the area again I'll go
just for the hell of it!

If you want new try RS components.

Thanks but I have plenty of sources for new - RS would be the last
place I would go (unless it was post 5pm desperate need for the next
day) I would suspect they would only do Metric coarse anyway - most
of my left hand requirements would be for UNF or Metric Fine. For the
bolt I would turn from scratch and screwcut in a few minutes rather
than even contemplate using a die.

But back to the original problem - left handed tapping and using a
left handed bolt is a crazy idea!



--

On Wed, 16 Nov 2005 16:32:23 +0000 (GMT), "Dave Plowman (News)"
wrote:

In article ,
The3rd Earl Of Derby wrote:
Use this instead.
http://www.machinemart.co.uk/product...0&r=2080&g=111

Trouble with these is they often break and then you can't drill the
hardened steel out. If buying easy outs go to a good quality tool shop or
engineer's suppliers. And pay for the best.

But even the "best" break :-)


--

is the cast iron removable from where it is fixed?
if so get it to an engineering shop and get them to do it

"Chris Bacon" wrote in message
...
Having to remove the ends of some sheared off bolts in
cast iron, I wonder what's the best way (preserving the
threads in the hole as much as possible) to do this.

I ran some 2mm drills down the threads, one on each side,
then a larger hole down the middle to join, as near as
possible, the two smaller ones:

,-.
' '
o O o - holes drilled down each
` ' side of bolt/threaded hole
`-'

Apologies for the dodgy ASCII art. The bits of bolt left
in the hole could then be worked out, leaving usable
threads.

Is there a better way, using a hand-held electric drill?

Spark erosion might be another way (but not exactly
"portable") - other ideas?

Guy King wrote:
The message from Chris Bacon contains these words:
Use this instead.
http://www.machinemart.co.uk/product...0&r=2080&g=111

Unless the're really good ones, they just snap off 'cos the Chinese
don't understand proper case-hardening.

Good Lord, are they *really* case-hardened? I am surprised.

Properly done, case hardening would be ideal for this application.

Hm, not sure about that, I think that these things are generally
hardened and tempered - the materials for these processes are
generally different, low carbon steel being used for case hardened
things. Very long time since I did any metallurgy, which I haven't
looked at since!

Matt wrote:
On Wed, 16 Nov 2005 16:32:23 +0000 (GMT), "Dave Plowman (News)"
wrote:


In article ,
The3rd Earl Of Derby wrote:

Use this instead.
http://www.machinemart.co.uk/product...0&r=2080&g=111

Trouble with these is they often break and then you can't drill the
hardened steel out. If buying easy outs go to a good quality tool shop or
engineer's suppliers. And pay for the best.


But even the "best" break :-)

When they do, just drill them out.
You will need a solid tungsten carbide twist drill though.
Local engineers supplier will have one.

Dave

Chris Bacon wrote:

Having to remove the ends of some sheared off bolts in
cast iron, I wonder what's the best way (preserving the
threads in the hole as much as possible) to do this.

I ran some 2mm drills down the threads, one on each side,
then a larger hole down the middle to join, as near as
possible, the two smaller ones:

,-.
' '
o O o - holes drilled down each
` ' side of bolt/threaded hole
`-'

Apologies for the dodgy ASCII art. The bits of bolt left
in the hole could then be worked out, leaving usable
threads.

Is there a better way, using a hand-held electric drill?

Spark erosion might be another way (but not exactly
"portable") - other ideas?

What size are the sheared studs?

It makes a big difference to the tactics that you can use.

Dave

Ok,
these are my methods, you may like em or not. Most of this is practiced
on motorbikes and have all worked at one time or other, saving me a
buyndle on heli-coiling and whatnot.

Before you do any of these, allways heat the bolts and then spray
chilled water on em, I think it breaks any bonds that the threads have
made with the each other. then:

1: use a hacksaw blade or one of those dinky little dremel jobbies to
cut a "slot" on the stub that is left over. If the stub is flush with
the rest of the metal, I'd cut the slot anyway, and then repair the
"colateral damage" on the surrounding area (solder, metal-epox,
whatever), after the stud is extracted. When you have a slot, heat
again and turn with a flat blade SD- heating is not advisable if the
stud expands faster than the hole, for obvious reasons. I tend to use
impact with a hammer as I turn, to give it the best chance of
unscrewing.

2: If the bolt is large (10mm+) you could go through all the
superheat/chill mallarkey and then turn the stub with some well placed
tangential blows with a punch and hammer.

3: Use the Snap-On stud extractor bit (which by the way was stolen from
me, and I swear by the almighty that if I find the dirty weazel I will
feed his swingers into my bike's chain), good stuff anyway.

Hope this helps.

"Dave" wrote in message
...
Matt wrote:
On Wed, 16 Nov 2005 16:32:23 +0000 (GMT), "Dave Plowman (News)"
wrote:


In article ,
The3rd Earl Of Derby wrote:

Use this instead.
http://www.machinemart.co.uk/product...0&r=2080&g=111

Trouble with these is they often break and then you can't drill
the
hardened steel out. If buying easy outs go to a good quality tool
shop or
engineer's suppliers. And pay for the best.


But even the "best" break :-)

When they do, just drill them out.
You will need a solid tungsten carbide twist drill though.
Local engineers supplier will have one.

Dave

If the stud is sheared off flush with a surface, place a nut over it
and mig weld the stud end until the blob of metal is big enough to
fuse to the nut. When it cools remove with a spanner. Obviously not
applicable to flamable objects, but in iron, steel and aluminium the
heat of the welding expands the stud, when it cools it will be freer
than it was and now you have something the grab!

AWEM

In message , somebody
writes
In message , Chris Bacon
writes
Having to remove the ends of some sheared off bolts in
cast iron, I wonder what's the best way (preserving the
threads in the hole as much as possible) to do this.

[..]

Is there a better way, using a hand-held electric drill?


1 - Easy Out

Has anybody anywhere ever actually successfully used one of these things
?


2 - Left handed drill bit

.... From tracey Tools, although exactly how a LH drill bit would
necessarily remove the remains of a bolt, I'm not so sure


Hth
Someone

--
geoff

"Dave" wrote in message
...
Chris Bacon wrote:

Having to remove the ends of some sheared off bolts in
cast iron, I wonder what's the best way (preserving the
threads in the hole as much as possible) to do this.

I ran some 2mm drills down the threads, one on each side,
then a larger hole down the middle to join, as near as
possible, the two smaller ones:

,-.
' '
o O o - holes drilled down each
` ' side of bolt/threaded hole
`-'

Apologies for the dodgy ASCII art. The bits of bolt left
in the hole could then be worked out, leaving usable
threads.

Is there a better way, using a hand-held electric drill?

Spark erosion might be another way (but not exactly
"portable") - other ideas?

What size are the sheared studs?

It makes a big difference to the tactics that you can use.

Dave

8mm