I'm having difficulty drilling out pop rivets. Are they made or something
that work hardens or something? Or have I just got naff drill bits? Or is a
cheap cordless drill not up to the job?

On Sun, 19 Aug 2007 19:12:47 +0100, Doki wrote:

I'm having difficulty drilling out pop rivets. Are they made or
something that work hardens or something? Or have I just got naff drill
bits? Or is a cheap cordless drill not up to the job?


The bit of steel that snaps is high carbon steel, the trick is to either
use exactly the right size drill bit or very carefully a slightly too big
one & stop when you've cut the flange and or reemove the centre popped bit
by knocking it out with a small centre punch before drilling.

Duncan Wood wrote:
On Sun, 19 Aug 2007 19:12:47 +0100, Doki wrote:

I'm having difficulty drilling out pop rivets. Are they made or
something that work hardens or something? Or have I just got naff
drill bits? Or is a cheap cordless drill not up to the job?


The bit of steel that snaps is high carbon steel, the trick is to either
use exactly the right size drill bit or very carefully a slightly too
big one & stop when you've cut the flange and or reemove the centre
popped bit by knocking it out with a small centre punch before drilling.

Also, make sure the little buggers aren't just spinning merrily in the hole.

DAMHIKT.

In article op.txbjy6gfyuobwl@lucy,
"Duncan Wood" writes:
On Sun, 19 Aug 2007 19:12:47 +0100, Doki wrote:

I'm having difficulty drilling out pop rivets. Are they made or
something that work hardens or something? Or have I just got naff drill
bits? Or is a cheap cordless drill not up to the job?

The bit of steel that snaps is high carbon steel, the trick is to either
use exactly the right size drill bit or very carefully a slightly too big
one & stop when you've cut the flange and or reemove the centre popped bit
by knocking it out with a small centre punch before drilling.

Sometimes the rivit spins with the drill bit. Holding the drill
at an angle will mean it still cuts the rivit (even though it
may still spin).

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

"Duncan Wood" wrote in message
newsp.txbjy6gfyuobwl@lucy...
On Sun, 19 Aug 2007 19:12:47 +0100, Doki wrote:

I'm having difficulty drilling out pop rivets. Are they made or
something that work hardens or something? Or have I just got naff drill
bits? Or is a cheap cordless drill not up to the job?


The bit of steel that snaps is high carbon steel, the trick is to either
use exactly the right size drill bit or very carefully a slightly too big
one & stop when you've cut the flange and or reemove the centre popped bit
by knocking it out with a small centre punch before drilling.

Sometimes the remainder of the bit that snaps is left at various lengths,
which makes for difficulties in properly penetrating the rivet with the
drill. The other thing that can happen, fairly frequently in my experience,
is that the drill bit may start the rivet turning in it's hole,
necessitating pliers/ mole grips on the back, if it's accessible, or tears
if it's not.

On Sun, 19 Aug 2007 19:22:08 +0100, "Duncan Wood" wrote:

On Sun, 19 Aug 2007 19:12:47 +0100, Doki wrote:

I'm having difficulty drilling out pop rivets. Are they made or
something that work hardens or something? Or have I just got naff drill
bits? Or is a cheap cordless drill not up to the job?


The bit of steel that snaps is high carbon steel, the trick is to either
use exactly the right size drill bit or very carefully a slightly too big
one & stop when you've cut the flange and or reemove the centre popped bit
by knocking it out with a small centre punch before drilling.

...or a drill that is much too big, so enough of the side gets cut away before the tip hits the hard
bit. Rocking/swivelling in cone-like motion while drilling with an oversize bit can also help cut
away the 'corner'

I'm having difficulty drilling out pop rivets. Are they made or
something that work hardens or something? Or have I just got naff drill
bits? Or is a cheap cordless drill not up to the job?

The bit of steel that snaps is high carbon steel, the trick is to either

The HCS mandrel is the least of your worries as you'll usually find it can
be tapped through and out the other side of the (alloy) blind rivet, unles
it is of the closed end type. If you are drilling pop rivets in your car I
suggest using the right drill speed for an 'average' aluminium alloy, and
make sure your drill is sharp.

If you are drilling rivets in a boat/yacht you'll find that they are likely
to be made of Monel metal, similar to one of the popular Stainless steels.
This will work harden as a result of the heat of drilling too fast. Start
slow. Really slow, and just let it squeal and chatter. You might try using
a cutting fluid or (Last resort) a squirty bottle full of water, just to
keep drill and rivet cool. Mind the water if you are using a drill that
plugs into the mains.... When you finish, then will be time to re-sharpen
your drill.

A

"Doki" wrote in message
...
I'm having difficulty drilling out pop rivets. Are they made or something
that work hardens or something? Or have I just got naff drill bits? Or is
a cheap cordless drill not up to the job?

tap out the centre, then drill. A sharp thin chisel is often the fastest,
easiest method.

Doki wrote:

I'm having difficulty drilling out pop rivets. Are they made or
something that work hardens or something? Or have I just got naff drill
bits? Or is a cheap cordless drill not up to the job?

There are two types of pop rivet.

The first one is called a 'break stem' and as suggested leaves part of
the stem locked inside the rivet. The ball that swells the rivet is
trapped inside the rivet

The second types is know as a break head and this lets the ball that
sets the rivet fall out of the rivet.

Obviously, when you use a rivet in an enclosed blind area, you do not
want bits of it ratting around after you pull and set them, so you chose
a break stem type.

As others have said, it is possible for the rivet to revolve when trying
to drill it out. just hold the driven twist dill at an angle of about 30
degrees from the direction of the rivet and you will be able to get the
head of the rivet off. If the tail remains, just use a punch and it will
fall out.

I have nearly 30 years experience of this.

HTH

Dave

On Sun, 19 Aug 2007 20:53:19 +0000, Mrcheerful wrote:


"Doki" wrote in message
...
I'm having difficulty drilling out pop rivets. Are they made or
something that work hardens or something? Or have I just got naff drill
bits? Or is a cheap cordless drill not up to the job?

snipped

A sharp thin chisel is often
the fastest, easiest method.

==================================
I agree, I find this method works very well. A sharp tap with a hammer
on an old (but sharp) wood chisel can be used to slice the top off the
rivet.

If you've got space a very light touch with an angle grinder will also do
the job, and the remains of the rivet can be tapped through the hole.

When I do use a drill, I find that a fairly big drill works best - about
3/8".

Cic.

--
===================================
Using Ubuntu Linux
Windows shown the door
===================================

"Dave" wrote in message
...
Doki wrote:

I'm having difficulty drilling out pop rivets. Are they made or something
that work hardens or something? Or have I just got naff drill bits? Or is
a cheap cordless drill not up to the job?

There are two types of pop rivet.

The first one is called a 'break stem' and as suggested leaves part of the
stem locked inside the rivet. The ball that swells the rivet is trapped
inside the rivet

The second types is know as a break head and this lets the ball that sets
the rivet fall out of the rivet.

Obviously, when you use a rivet in an enclosed blind area, you do not want
bits of it ratting around after you pull and set them, so you chose a
break stem type.

As others have said, it is possible for the rivet to revolve when trying
to drill it out. just hold the driven twist dill at an angle of about 30
degrees from the direction of the rivet and you will be able to get the
head of the rivet off. If the tail remains, just use a punch and it will
fall out.

It's not spinning around uselessly, thankfully. I suspect my problems are
down to either crap drill bits or the stem still being in there.

I have nearly 30 years experience of this.

Excellent.

Adam H wrote:
I'm having difficulty drilling out pop rivets. Are they made or
something that work hardens or something? Or have I just got naff
drill bits? Or is a cheap cordless drill not up to the job?

The bit of steel that snaps is high carbon steel, the trick is to
either

The HCS mandrel is the least of your worries as you'll usually find
it can be tapped through and out the other side of the (alloy) blind
rivet, unles it is of the closed end type. If you are drilling pop
rivets in your car I suggest using the right drill speed for an
'average' aluminium alloy, and make sure your drill is sharp.

If you are drilling rivets in a boat/yacht you'll find that they are
likely to be made of Monel metal, similar to one of the popular
Stainless steels. This will work harden as a result of the heat of
drilling too fast. Start slow. Really slow, and just let it squeal
and chatter. You might try using a cutting fluid or (Last resort) a
squirty bottle full of water, just to keep drill and rivet cool. Mind the
water if you are using a drill that plugs into the mains....
When you finish, then will be time to re-sharpen your drill.

I'd agree completely with that. Usually ally rivets drill out easily, but
if they are marine grade a cobalt drill will help no end.


--
Dave
The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

In article ,
Doki wrote:
I'm having difficulty drilling out pop rivets. Are they made or
something that work hardens or something? Or have I just got naff drill
bits? Or is a cheap cordless drill not up to the job?

Most are ally and drill out easily. However, the 'pip' that breaks off the
shank is sometimes close to the head and that's hard steel. Which will
stop the drill. Punch it out first with a shank.

--
*Oh, what a tangled website we weave when first we practice *

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

Doki wrote:
"Dave" wrote in message
...
Doki wrote:

I'm having difficulty drilling out pop rivets. Are they made or something
that work hardens or something? Or have I just got naff drill bits? Or is
a cheap cordless drill not up to the job?

There are two types of pop rivet.

The first one is called a 'break stem' and as suggested leaves part of the
stem locked inside the rivet. The ball that swells the rivet is trapped
inside the rivet

The second types is know as a break head and this lets the ball that sets
the rivet fall out of the rivet.

Obviously, when you use a rivet in an enclosed blind area, you do not want
bits of it ratting around after you pull and set them, so you chose a
break stem type.

As others have said, it is possible for the rivet to revolve when trying
to drill it out. just hold the driven twist dill at an angle of about 30
degrees from the direction of the rivet and you will be able to get the
head of the rivet off. If the tail remains, just use a punch and it will
fall out.

It's not spinning around uselessly, thankfully. I suspect my problems are
down to either crap drill bits or the stem still being in there.

I have nearly 30 years experience of this.

Excellent.

I suspect a bad drill bit or the fact youre using a cheap cordless. A
mains drill would be way quicker.

The other option not yet mentioned is to use wire cutters of the flush
cutting type - these have no angle ground on one side and will cut
flush. They can snip
ali rivets off with one squeeeze.

Re the steel bit in the middle, apply a nail and give it a tap.

The last thing is that standard HSS twist drills dont work that good
on ali, try a gold coloured coated bit instead.

Angle grinders are quick on rivets, but they do make a mess of the
surrounding metal.


NT

In article . com,
wrote:
The last thing is that standard HSS twist drills dont work that good
on ali, try a gold coloured coated bit instead.

First I've heard of this. ;-)

--
*Prepositions are not words to end sentences with *

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

wrote in message
ups.com...

The last thing is that standard HSS twist drills dont work that good
on ali, try a gold coloured coated bit instead..

Sorry, but that is just plain nonsense.

A gold coloured bit usually means it is a HSS drill bit with a Titanium
nitride coating, TiN, which gives it a harder surface finish than plain HSS.

Ally being a soft material is easily drilled using plain HSS bits. Even
carbon steel drill bits have little trouble drilling ally. Certainly no
problem drilling pop rivet material apart from the pins themselves.

Another point about TiN coated bits is that sharpening removes the TiN from
the cutting edge. They are then no better than plain HHS bits.

IME as an engineer, a set of HSS drill bits is as good as any for drilling
all the but the toughest material.

It also helps if you know how to resharpen them.
Mike.

Dave Plowman (News) wrote:
In article . com,
wrote:

The last thing is that standard HSS twist drills dont work that good
on ali, try a gold coloured coated bit instead.


First I've heard of this. ;-)

Me too and I have spent most of my working life in the aerospace
industry teaching others to drill difficult metals.

Dave

On Mon, 20 Aug 2007 14:07:43 +0100, Mike G wrote:


wrote in message
ups.com...

The last thing is that standard HSS twist drills dont work that good
on ali, try a gold coloured coated bit instead..

Sorry, but that is just plain nonsense.

A gold coloured bit usually means it is a HSS drill bit with a Titanium
nitride coating, TiN, which gives it a harder surface finish than plain
HSS.

Ally being a soft material is easily drilled using plain HSS bits. Even
carbon steel drill bits have little trouble drilling ally. Certainly no
problem drilling pop rivet material apart from the pins themselves.

Another point about TiN coated bits is that sharpening removes the TiN
from the cutting edge. They are then no better than plain HHS bits.

IME as an engineer, a set of HSS drill bits is as good as any for
drilling all the but the toughest material.

It also helps if you know how to resharpen them.
Mike.


The only thing that might make a difference is that drills with a large
included point angle for drilling alloys where often TiN coated & they're
also quite good for drillin pop rivets out without snatching.

Dave Plowman (News) wrote:
In article . com,
wrote:
The last thing is that standard HSS twist drills dont work that good
on ali, try a gold coloured coated bit instead.

First I've heard of this. ;-)


No, it's true. gold coloured things work better.

Otherwise why would the goldy coloured car parts in Halfords be twice
the price of the ordinary ones?

Answer me that, eh?

On Mon, 20 Aug 2007 21:29:22 +0100, PC Paul wrote:

Dave Plowman (News) wrote:
In article . com,
wrote:
The last thing is that standard HSS twist drills dont work that good
on ali, try a gold coloured coated bit instead.
First I've heard of this. ;-)


No, it's true. gold coloured things work better.

Otherwise why would the goldy coloured car parts in Halfords be twice
the price of the ordinary ones?

Answer me that, eh?


Golds really corrosion resistant?

Duncan Wood wrote:
On Mon, 20 Aug 2007 21:29:22 +0100, PC Paul wrote:

Dave Plowman (News) wrote:
In article . com,
wrote:
The last thing is that standard HSS twist drills dont work that good
on ali, try a gold coloured coated bit instead.
First I've heard of this. ;-)


No, it's true. gold coloured things work better.

Otherwise why would the goldy coloured car parts in Halfords be twice
the price of the ordinary ones?

Answer me that, eh?


Golds really corrosion resistant?

Gold 'coloured'.

In message , PC Paul
writes
Dave Plowman (News) wrote:
In article . com,
wrote:
The last thing is that standard HSS twist drills dont work that good
on ali, try a gold coloured coated bit instead.
First I've heard of this. ;-)


No, it's true. gold coloured things work better.


.... Runs out to buy some gold body paint


--
geoff

raden wrote:
In message , PC Paul
writes
Dave Plowman (News) wrote:
In article . com,
wrote:
The last thing is that standard HSS twist drills dont work that
good on ali, try a gold coloured coated bit instead.
First I've heard of this. ;-)


No, it's true. gold coloured things work better.


... Runs out to buy some gold body paint

Only a small tin though :-)


--
Dave
The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

On Mon, 20 Aug 2007 21:50:13 +0100, PC Paul wrote:

Duncan Wood wrote:
On Mon, 20 Aug 2007 21:29:22 +0100, PC Paul wrote:

Dave Plowman (News) wrote:
In article . com,
wrote:
The last thing is that standard HSS twist drills dont work that good
on ali, try a gold coloured coated bit instead.
First I've heard of this. ;-)


No, it's true. gold coloured things work better.

Otherwise why would the goldy coloured car parts in Halfords be twice
the price of the ordinary ones?

Answer me that, eh?
Golds really corrosion resistant?

Gold 'coloured'.




I know....

In message , The Medway Handyman
writes
raden wrote:
In message , PC Paul
writes
Dave Plowman (News) wrote:
In article . com,
wrote:
The last thing is that standard HSS twist drills dont work that
good on ali, try a gold coloured coated bit instead.
First I've heard of this. ;-)


No, it's true. gold coloured things work better.


... Runs out to buy some gold body paint

Only a small tin though :-)

Ah, but you rub this stuff on !

--
geoff

In message , cerberus
writes

"cerberus" wrote in message
.uk...

"Duncan Wood" wrote in message
newsp.txdkgxvfyuobwl@lucy...
On Mon, 20 Aug 2007 14:07:43 +0100, Mike G wrote:


wrote in message
ups.com...


The biggest problem with with 'pop' rivets is whether they are open or
closed. An open rivet is relatively easy to drill out.....it's just a
matter of knocking the 'mandrel' out (the piece that expands the rivet) &
then drilling the head off, then the shank can be 'knocked through' with a
centre punch!

A 'closed' rivet is a different kettle of fish, normally the mandrel
cannot be knocked back...it's a matter of drilling the 'head' off & then
knocking back with a punch and expanding the origional hole.


When is a pop rivet not a pop rivet?

When it's a monobolt http://www.erivet.co.uk/monobolt.htm

Our biology teacher carried the nickname bolt, due to a scar on the neck

just thought you should know that


--
geoff

raden wrote:
In message , The Medway
Handyman writes
raden wrote:
In message , PC
Paul writes
Dave Plowman (News) wrote:
In article . com,
wrote:
The last thing is that standard HSS twist drills dont work that
good on ali, try a gold coloured coated bit instead.
First I've heard of this. ;-)


No, it's true. gold coloured things work better.


... Runs out to buy some gold body paint

Only a small tin though :-)

Ah, but you rub this stuff on !

So, you start with a small tin........................


--
Dave
The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

"Duncan Wood" wrote in message
newsp.txdkgxvfyuobwl@lucy...
On Mon, 20 Aug 2007 14:07:43 +0100, Mike G wrote:


wrote in message
ups.com...

The last thing is that standard HSS twist drills dont work that good
on ali, try a gold coloured coated bit instead..

Sorry, but that is just plain nonsense.

A gold coloured bit usually means it is a HSS drill bit with a Titanium
nitride coating, TiN, which gives it a harder surface finish than plain
HSS.

Ally being a soft material is easily drilled using plain HSS bits. Even
carbon steel drill bits have little trouble drilling ally. Certainly no
problem drilling pop rivet material apart from the pins themselves.

Another point about TiN coated bits is that sharpening removes the TiN
from the cutting edge. They are then no better than plain HHS bits.

IME as an engineer, a set of HSS drill bits is as good as any for
drilling all the but the toughest material.

It also helps if you know how to resharpen them.
Mike.


The only thing that might make a difference is that drills with a large
included point angle for drilling alloys where often TiN coated & they're
also quite good for drillin pop rivets out without snatching.

I know text books talk about different included angles for different
materials, but in practice, engineers in jobbing shops just grind a drill by
hand so it cuts. Maybe variations when drilling plastics , resin bonded
materials etc, otherwise they're all ground the same.
TBH, unless used on a production m/c I see little point in using TiN coated
drills, as once they need sharpening any cutting advantage is lost, and they
will need sharpening, especially if used in hand held electric drills.
A set of HSS drills will last for years. Just needing the occasional
sharpening to keep them in a serviceable condition.
The HSS drill sets I have at work are at least 15 years old. A few bits have
been replaced through breakage or loss, but the majority came with the set
when purchased.
Mike.

"Duncan Wood" wrote in message
newsp.txdkgxvfyuobwl@lucy...
On Mon, 20 Aug 2007 14:07:43 +0100, Mike G wrote:


wrote in message
ups.com...

The last thing is that standard HSS twist drills dont work that good
on ali, try a gold coloured coated bit instead..

Sorry, but that is just plain nonsense.

A gold coloured bit usually means it is a HSS drill bit with a Titanium
nitride coating, TiN, which gives it a harder surface finish than plain
HSS.

Ally being a soft material is easily drilled using plain HSS bits. Even
carbon steel drill bits have little trouble drilling ally. Certainly no
problem drilling pop rivet material apart from the pins themselves.

Another point about TiN coated bits is that sharpening removes the TiN
from the cutting edge. They are then no better than plain HHS bits.

IME as an engineer, a set of HSS drill bits is as good as any for
drilling all the but the toughest material.

It also helps if you know how to resharpen them.
Mike.


The only thing that might make a difference is that drills with a large
included point angle for drilling alloys where often TiN coated & they're
also quite good for drillin pop rivets out without snatching.

The biggest problem with with 'pop' rivets is whether they are open or
closed. An open rivet is relatively easy to drill out.....it's just a matter
of knocking the 'mandrel' out (the piece that expands the rivet) & then
drilling the head off, then the shank can be 'knocked through' with a centre
punch!

A 'closed' rivet is a different kettle of fish, normally the mandrel cannot
be knocked back...it's a matter of drilling the 'head' off & then knocking
back with a punch and expanding the origional hole.

"cerberus" wrote in message
. uk...

"Duncan Wood" wrote in message
newsp.txdkgxvfyuobwl@lucy...
On Mon, 20 Aug 2007 14:07:43 +0100, Mike G wrote:


wrote in message
ups.com...


The biggest problem with with 'pop' rivets is whether they are open or
closed. An open rivet is relatively easy to drill out.....it's just a
matter of knocking the 'mandrel' out (the piece that expands the rivet) &
then drilling the head off, then the shank can be 'knocked through' with a
centre punch!

A 'closed' rivet is a different kettle of fish, normally the mandrel
cannot be knocked back...it's a matter of drilling the 'head' off & then
knocking back with a punch and expanding the origional hole.


When is a pop rivet not a pop rivet?

When it's a monobolt http://www.erivet.co.uk/monobolt.htm

PC Paul wrote:
Duncan Wood wrote:
On Mon, 20 Aug 2007 21:29:22 +0100, PC Paul wrote:
Dave Plowman (News) wrote:
In article . com,
wrote:

The last thing is that standard HSS twist drills dont work that good
on ali, try a gold coloured coated bit instead.
First I've heard of this. ;-)


No, it's true. gold coloured things work better.

Otherwise why would the goldy coloured car parts in Halfords be twice
the price of the ordinary ones?

Answer me that, eh?


Golds really corrosion resistant?

Gold 'coloured'.

Gold coloured drill bits are tough low friction titanium alloy coated,
TiN or TiAlN.


NT

Mike G wrote:
wrote in message
ups.com...

The last thing is that standard HSS twist drills dont work that good
on ali, try a gold coloured coated bit instead..

Sorry, but that is just plain nonsense.

well I'll take your word for it. I thought ali tended to stick to hss
at higher speeds.


NT

Mike G wrote:

TBH, unless used on a production m/c I see little point in using TiN coated
drills, as once they need sharpening any cutting advantage is lost, and they
will need sharpening, especially if used in hand held electric drills.
A set of HSS drills will last for years. Just needing the occasional
sharpening to keep them in a serviceable condition.
The HSS drill sets I have at work are at least 15 years old. A few bits have
been replaced through breakage or loss, but the majority came with the set
when purchased.
Mike.

AIUI the advantage is that Ti coated bits have longer life to first
resharpen, thus for a DIYer that means less time out of service. The
other plus is that since most DIYers dont resharpen bits, the Ti
coated ones will last longer, easily justifying the extra cost.
Probably all DIYers should resharpen bits, but IRL most dont.


NT

In article . com,
wrote:
AIUI the advantage is that Ti coated bits have longer life to first
resharpen, thus for a DIYer that means less time out of service. The
other plus is that since most DIYers dont resharpen bits, the Ti
coated ones will last longer, easily justifying the extra cost.
Probably all DIYers should resharpen bits, but IRL most dont.

Wish there was a decent drill sharpener on the market. I have two and
they're both near useless on anything other than large drills. Which even
I can do as well on a grinder by eye.

--
*I went to school to become a wit, only got halfway through.

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

"Dave Plowman (News)" wrote in message
...
In article . com,
wrote:
AIUI the advantage is that Ti coated bits have longer life to first
resharpen, thus for a DIYer that means less time out of service. The
other plus is that since most DIYers dont resharpen bits, the Ti
coated ones will last longer, easily justifying the extra cost.
Probably all DIYers should resharpen bits, but IRL most dont.

Wish there was a decent drill sharpener on the market. I have two and
they're both near useless on anything other than large drills. Which even
I can do as well on a grinder by eye.

That's the way all real engineers sharpen drill bits. :-)

Seriously though, a proper drill sharpener is an expensive precision piece
of equipment, and not worth buying for sharpening the odd drill.
Mike.

wrote in message
ups.com...
Mike G wrote:

TBH, unless used on a production m/c I see little point in using TiN
coated
drills, as once they need sharpening any cutting advantage is lost, and
they
will need sharpening, especially if used in hand held electric drills.
A set of HSS drills will last for years. Just needing the occasional
sharpening to keep them in a serviceable condition.
The HSS drill sets I have at work are at least 15 years old. A few bits
have
been replaced through breakage or loss, but the majority came with the
set
when purchased.
Mike.

AIUI the advantage is that Ti coated bits have longer life to first
resharpen, thus for a DIYer that means less time out of service. The
other plus is that since most DIYers dont resharpen bits, the Ti
coated ones will last longer, easily justifying the extra cost.

I disagree. TiN coated drills don't last well in hand held grinders.
In that application I doubt they last much longer than plain HSS ones.

Probably all DIYers should resharpen bits, but IRL most dont.

I suspect most DIYers have facilities for grinding drills, even if it's only
an angle grinder. If they can't sharpen a drill, they should learn how to.
Far cheaper than buying a new drill bit when it becomes blunt.
Mike.

In message , Mike G
writes
The HSS drill sets I have at work are at least 15 years old. A few bits
have been replaced through breakage or loss, but the majority came with
the set when purchased.
Trigger's Broom springs to mind...
Mike.
My dad was a lathe operator in a small engineering firm, he had drill
bits and tools from his apprenticeship that he still used daily, had to
be over 40 yrs old.
--
Clint Sharp

"Clint Sharp" wrote in message
...
In message , Mike G
writes
The HSS drill sets I have at work are at least 15 years old. A few bits
have been replaced through breakage or loss, but the majority came with
the set when purchased.

Trigger's Broom springs to mind...

Not really. 75% of them are the originals.
Most of those replaced have been under 5mm in diameter.
Small drills, especially the very small sizes are easily lost or broken.
And I also have boxes of miscellaneous drills. Many of which date back to my
early years in engineering.

My dad was a lathe operator in a small engineering firm, he had drill bits
and tools from his apprenticeship that he still used daily, had to be over
40 yrs old.

Prexactly.
Mike.

Mike G wrote:

wrote in message
ups.com...

The last thing is that standard HSS twist drills dont work that good
on ali, try a gold coloured coated bit instead..


Sorry, but that is just plain nonsense.

A gold coloured bit usually means it is a HSS drill bit with a Titanium
nitride coating, TiN, which gives it a harder surface finish than plain
HSS.

And once ground, will only stop aluminium from sticking to the flutes of
the drill.

Ally being a soft material is easily drilled using plain HSS bits. Even
carbon steel drill bits have little trouble drilling ally. Certainly no
problem drilling pop rivet material apart from the pins themselves.

At this point, I should add that most pop rivets are made from monel
metal. The aluminium ones are usually bought from the local pound shop.
I suspect the original question was about a monel metal rivet that was
spinning round. Tilt the drill to about 30 degrees and you will drill
off the head, just stop drilling before you go all the way through and
try a punch to break what is left of the head. If it does not easily
break the head of the rivet, drill again at 30 degrees.

Another point about TiN coated bits is that sharpening removes the TiN
from the cutting edge. They are then no better than plain HHS bits.

IME as an engineer, a set of HSS drill bits is as good as any for
drilling all the but the toughest material.

It also helps if you know how to resharpen them.

You and I know that. Try telling those that can't ;-)

I once had a job trying to drill through some umpteen thousand ton
steel, using a D 200 drill of 2.5 mm. I spent more time walking to the
grind stone than drilling. The twist drill showed nothing wrong, but it
wouldn't drill any more. Grind it and it would drill another three holes
and so it went on for a few weeks. Umpteen holes in this job :-(

The Italians, who were responsible for the job we were doing came round
to see how we were doing. One of the lads that was opening up the holes
to full size had turned the epoxy primer, around one hole, to a light
blue colour. The Italian rep turned round and said 'your drill is too
blunt'. The lad turned round and said 'your steel is too hard'.

The Italian turned back to him and said 'The designer, we should take
him around the corner and keel him'. Made me laugh when he told me though

Dave

cerberus wrote:

"Duncan Wood" wrote in message
newsp.txdkgxvfyuobwl@lucy...

On Mon, 20 Aug 2007 14:07:43 +0100, Mike G wrote:


wrote in message
groups.com...


The last thing is that standard HSS twist drills dont work that good
on ali, try a gold coloured coated bit instead..

Sorry, but that is just plain nonsense.

A gold coloured bit usually means it is a HSS drill bit with a Titanium
nitride coating, TiN, which gives it a harder surface finish than plain
HSS.

Ally being a soft material is easily drilled using plain HSS bits. Even
carbon steel drill bits have little trouble drilling ally. Certainly no
problem drilling pop rivet material apart from the pins themselves.

Another point about TiN coated bits is that sharpening removes the TiN
from the cutting edge. They are then no better than plain HHS bits.

IME as an engineer, a set of HSS drill bits is as good as any for
drilling all the but the toughest material.

It also helps if you know how to resharpen them.
Mike.


The only thing that might make a difference is that drills with a large
included point angle for drilling alloys where often TiN coated & they're
also quite good for drillin pop rivets out without snatching.


The biggest problem with with 'pop' rivets is whether they are open or
closed. An open rivet is relatively easy to drill out.....it's just a matter
of knocking the 'mandrel' out (the piece that expands the rivet) & then
drilling the head off, then the shank can be 'knocked through' with a centre
punch!

A 'closed' rivet is a different kettle of fish, normally the mandrel cannot
be knocked back...it's a matter of drilling the 'head' off & then knocking
back with a punch and expanding the origional hole.

Pop rivets can be divided into 3 types.

The first 2 types are made from monel metal and the third from crappy
aluminium.

The monel metal ones can be sub devided into break head and break stem.

A break stem retains the lower part of the manderl that is used to
expand the rivet on the blind side. This is done, so that there are no
loose items left on the blind side. This stem can ususally be removed,
providing the structure it has been set in is firm and not bouncy, by a
small punch with a 'quick' bang by a small hammer.

Break head, as the name sugeusts, is designied to let the pulled head of
the rivet to fall into the void of where the rivet was pulled. If this
void is capable of being cleaned out, everything is OK. If it isn't,
then some form of sealant has to be injected into it to prevent the
dross from harming the void. This pruduct is usually a bonding agent.

Dave