Screw removal tools

[Sylvia Else]

Anyone had any success with these?

In a triumph of hope over experience, I bought a set of three Irwin
brand screw removal tools. These have a drill at one end, and the spiral
thread kind of cone at the other end.

My problem always seems to be drilling the initial hole. In this case
what I would take to be cheap self-tapping screws seem to be made of
diamond.

Sylvia.

[Daryl]

Post by Sylvia Else
Anyone had any success with these?
In a triumph of hope over experience, I bought a set of three Irwin
brand screw removal tools. These have a drill at one end, and the spiral
thread kind of cone at the other end.
My problem always seems to be drilling the initial hole. In this case
what I would take to be cheap self-tapping screws seem to be made of
diamond.
Sylvia.

Possibly it won't drill because the particular tool you are using is
designed with the drill needed to be operated in the reverse direction?
AFAIK the idea is that the reverse drill bites into the screw head which
then unscrews it.

[Xeno]

Post by Daryl

Post by Sylvia Else
Anyone had any success with these?
In a triumph of hope over experience, I bought a set of three Irwin
brand screw removal tools. These have a drill at one end, and the
spiral thread kind of cone at the other end.
My problem always seems to be drilling the initial hole. In this case
what I would take to be cheap self-tapping screws seem to be made of
diamond.
Sylvia.

Possibly it won't drill because the particular tool you are using is
designed with the drill needed to be operated in the reverse direction?
AFAIK the idea is that the reverse drill bites into the screw head which
 then unscrews it.

The drill end is meant to rotate clockwise, the extractor end
anti-clockwise. I have such an extractor here somewhere, just not an
Irwin branded one. I don't expect the Irwin one to be any different

[Xeno]

Post by Sylvia Else
Anyone had any success with these?
In a triumph of hope over experience, I bought a set of three Irwin
brand screw removal tools. These have a drill at one end, and the spiral
thread kind of cone at the other end.
My problem always seems to be drilling the initial hole. In this case
what I would take to be cheap self-tapping screws seem to be made of
diamond.
Sylvia.

The problem is that self tapping screws are harder and the first problem
you will encounter is the drill trying to run off the centre. A simple
jig may serve here to keep the drill central. The next issue is the
hardness of the drill relative to the hardness of the extractor. The
extractors are harder (M2 High Speed Steel) but they may or may not be
harder than the self tapping screw. It certainly looks that way if you
are describing them as made of diamond.

Will you have any material left if you drill out the centre? The next
stage (other end) is nothing more than the standard ezy out type
extractor meant to rotate in reverse - albeit a bit shorter. Most self
tappers I've used don't have a lot of meat inside the flutes to even
drill a hole into much less get an extractor in there.

BTW, Irwin brands are only so so quality. Might not be hard enough.

[Sylvia Else]

Post by Xeno

Post by Sylvia Else
Anyone had any success with these?
In a triumph of hope over experience, I bought a set of three Irwin
brand screw removal tools. These have a drill at one end, and the
spiral thread kind of cone at the other end.
My problem always seems to be drilling the initial hole. In this case
what I would take to be cheap self-tapping screws seem to be made of
diamond.
Sylvia.

The problem is that self tapping screws are harder and the first problem
you will encounter is the drill trying to run off the centre. A simple
jig may serve here to keep the drill central. The next issue is the
hardness of the drill relative to the hardness of the extractor. The
extractors are harder (M2 High Speed Steel) but they may or may not be
harder than the self tapping screw. It certainly looks that way if you
are describing them as made of diamond.
Will you have any material left if you drill out the centre? The next
stage (other end) is nothing more than the standard ezy out type
extractor meant to rotate in reverse - albeit a bit shorter. Most self
tappers I've used don't have a lot of meat inside the flutes to even
drill a hole into much less get an extractor in there.
BTW, Irwin brands are only so so quality. Might not be hard enough.

I'd be content to drill the head entirely off, then get a vice-grip onto
what's left. Even some cobalt drill bits were struggling to make headway.

The heads themselves are nicely contoured to make gripping them
impossible. I tried to file some flats onto them, but that didn't work.

The available angle to approach is awkward anyway, and on one I
previously attacked, the bit was eventually slipping off the head
completely rather than drilling it any further.

Plan C involves an angle grinder.

Sylvia.

[Xeno]

Post by Sylvia Else

Post by Xeno

Post by Sylvia Else
Anyone had any success with these?
In a triumph of hope over experience, I bought a set of three Irwin
brand screw removal tools. These have a drill at one end, and the
spiral thread kind of cone at the other end.
My problem always seems to be drilling the initial hole. In this case
what I would take to be cheap self-tapping screws seem to be made of
diamond.
Sylvia.

The problem is that self tapping screws are harder and the first
problem you will encounter is the drill trying to run off the centre.
A simple jig may serve here to keep the drill central. The next issue
is the hardness of the drill relative to the hardness of the
extractor. The extractors are harder (M2 High Speed Steel) but they
may or may not be harder than the self tapping screw. It certainly
looks that way if you are describing them as made of diamond.
Will you have any material left if you drill out the centre? The next
stage (other end) is nothing more than the standard ezy out type
extractor meant to rotate in reverse - albeit a bit shorter. Most self
tappers I've used don't have a lot of meat inside the flutes to even
drill a hole into much less get an extractor in there.
BTW, Irwin brands are only so so quality. Might not be hard enough.

I'd be content to drill the head entirely off, then get a vice-grip onto
what's left. Even some cobalt drill bits were struggling to make headway.
The heads themselves are nicely contoured to make gripping them
impossible. I tried to file some flats onto them, but that didn't work.
The available angle to approach is awkward anyway, and on one I
previously attacked, the bit was eventually slipping off the head
completely rather than drilling it any further.
Plan C involves an angle grinder.
Sylvia.

Yeah, I was thinking you might need to do that.

[Sylvia Else]

Post by Xeno

Post by Sylvia Else

Post by Xeno

Post by Sylvia Else
Anyone had any success with these?
In a triumph of hope over experience, I bought a set of three Irwin
brand screw removal tools. These have a drill at one end, and the
spiral thread kind of cone at the other end.
My problem always seems to be drilling the initial hole. In this
case what I would take to be cheap self-tapping screws seem to be
made of diamond.
Sylvia.

The problem is that self tapping screws are harder and the first
problem you will encounter is the drill trying to run off the centre.
A simple jig may serve here to keep the drill central. The next issue
is the hardness of the drill relative to the hardness of the
extractor. The extractors are harder (M2 High Speed Steel) but they
may or may not be harder than the self tapping screw. It certainly
looks that way if you are describing them as made of diamond.
Will you have any material left if you drill out the centre? The next
stage (other end) is nothing more than the standard ezy out type
extractor meant to rotate in reverse - albeit a bit shorter. Most
self tappers I've used don't have a lot of meat inside the flutes to
even drill a hole into much less get an extractor in there.
BTW, Irwin brands are only so so quality. Might not be hard enough.

I'd be content to drill the head entirely off, then get a vice-grip
onto what's left. Even some cobalt drill bits were struggling to make
headway.
The heads themselves are nicely contoured to make gripping them
impossible. I tried to file some flats onto them, but that didn't work.
The available angle to approach is awkward anyway, and on one I
previously attacked, the bit was eventually slipping off the head
completely rather than drilling it any further.
Plan C involves an angle grinder.
Sylvia.

Yeah, I was thinking you might need to do that.

The angle grinder got the job done, though I wouldn't say it was easy. I
know that a grinding disc is sacrificial, but even so...

Sylvia.

[Xeno]

Post by Sylvia Else

Post by Xeno

Post by Sylvia Else

Post by Xeno

Post by Sylvia Else
Anyone had any success with these?
In a triumph of hope over experience, I bought a set of three Irwin
brand screw removal tools. These have a drill at one end, and the
spiral thread kind of cone at the other end.
My problem always seems to be drilling the initial hole. In this
case what I would take to be cheap self-tapping screws seem to be
made of diamond.
Sylvia.

The problem is that self tapping screws are harder and the first
problem you will encounter is the drill trying to run off the
centre. A simple jig may serve here to keep the drill central. The
next issue is the hardness of the drill relative to the hardness of
the extractor. The extractors are harder (M2 High Speed Steel) but
they may or may not be harder than the self tapping screw. It
certainly looks that way if you are describing them as made of diamond.
Will you have any material left if you drill out the centre? The
next stage (other end) is nothing more than the standard ezy out
type extractor meant to rotate in reverse - albeit a bit shorter.
Most self tappers I've used don't have a lot of meat inside the
flutes to even drill a hole into much less get an extractor in there.
BTW, Irwin brands are only so so quality. Might not be hard enough.

I'd be content to drill the head entirely off, then get a vice-grip
onto what's left. Even some cobalt drill bits were struggling to make
headway.
The heads themselves are nicely contoured to make gripping them
impossible. I tried to file some flats onto them, but that didn't work.
The available angle to approach is awkward anyway, and on one I
previously attacked, the bit was eventually slipping off the head
completely rather than drilling it any further.
Plan C involves an angle grinder.
Sylvia.

Yeah, I was thinking you might need to do that.

The angle grinder got the job done, though I wouldn't say it was easy. I
know that a grinding disc is sacrificial, but even so...
Sylvia.

Sometimes great sacrifice needs to be made in the name of progress! ;-)

[Trevor Wilson]

Post by Sylvia Else

Post by Xeno

Post by Sylvia Else
Anyone had any success with these?
In a triumph of hope over experience, I bought a set of three Irwin
brand screw removal tools. These have a drill at one end, and the
spiral thread kind of cone at the other end.
My problem always seems to be drilling the initial hole. In this case
what I would take to be cheap self-tapping screws seem to be made of
diamond.
Sylvia.

The problem is that self tapping screws are harder and the first
problem you will encounter is the drill trying to run off the centre.
A simple jig may serve here to keep the drill central. The next issue
is the hardness of the drill relative to the hardness of the
extractor. The extractors are harder (M2 High Speed Steel) but they
may or may not be harder than the self tapping screw. It certainly
looks that way if you are describing them as made of diamond.
Will you have any material left if you drill out the centre? The next
stage (other end) is nothing more than the standard ezy out type
extractor meant to rotate in reverse - albeit a bit shorter. Most self
tappers I've used don't have a lot of meat inside the flutes to even
drill a hole into much less get an extractor in there.
BTW, Irwin brands are only so so quality. Might not be hard enough.

I'd be content to drill the head entirely off, then get a vice-grip onto
what's left. Even some cobalt drill bits were struggling to make headway.
The heads themselves are nicely contoured to make gripping them
impossible. I tried to file some flats onto them, but that didn't work.
The available angle to approach is awkward anyway, and on one I
previously attacked, the bit was eventually slipping off the head
completely rather than drilling it any further.
Plan C involves an angle grinder.
Sylvia.

**My thoughts:

* If it is a small-ish screw, you could attack it with a Dremel™ fitted
with a grinding disk, so as to make a slot suitable for a flat blade
screwdriver. I've done this with lots of damaged Allen head screws.
* Make sure you have decent drills. There are plenty of really poor
quality drill bits available at Bunnings. There are a small number of
decent ones. Look for a genuine Aussie made one if you can. They
generally cost much more than the Chinese ones.

[Noddy]

Post by Trevor Wilson
* If it is a small-ish screw, you could attack it with a Dremel™ fitted
with a grinding disk, so as to make a slot suitable for a flat blade
screwdriver. I've done this with lots of damaged Allen head screws.
* Make sure you have decent drills. There are plenty of really poor
quality drill bits available at Bunnings. There are a small number of
decent ones. Look for a genuine Aussie made one if you can. They
generally cost much more than the Chinese ones.

I don't think anyone makes them in Australia anymore. Sutton used to be
the "go to" brand for quality stuff, but it's all made in China now.

[Xeno]

Post by Noddy

Post by Trevor Wilson
* If it is a small-ish screw, you could attack it with a Dremel™
fitted with a grinding disk, so as to make a slot suitable for a flat
blade screwdriver. I've done this with lots of damaged Allen head screws.
* Make sure you have decent drills. There are plenty of really poor
quality drill bits available at Bunnings. There are a small number of
decent ones. Look for a genuine Aussie made one if you can. They
generally cost much more than the Chinese ones.

I don't think anyone makes them in Australia anymore. Sutton used to be
the "go to" brand for quality stuff, but it's all made in China now.

Suttons still exists, still manufactures drill bits in Australia and now
own P&N, the company from which they bought drill blanks. I used to get
samples from the Suttons factory for use in teaching drill sharpening.

[Peter Jason]

Post by Xeno

Post by Noddy

* If it is a small-ish screw, you could attack it with a Dremel™
fitted with a grinding disk, so as to make a slot suitable for a flat
blade screwdriver. I've done this with lots of damaged Allen head screws.
* Make sure you have decent drills. There are plenty of really poor
quality drill bits available at Bunnings. There are a small number of
decent ones. Look for a genuine Aussie made one if you can. They
generally cost much more than the Chinese ones.

I don't think anyone makes them in Australia anymore. Sutton used to be
the "go to" brand for quality stuff, but it's all made in China now.

Suttons still exists, still manufactures drill bits in Australia and now
own P&N, the company from which they bought drill blanks. I used to get
samples from the Suttons factory for use in teaching drill sharpening.

I have a bucket-full of blunt twist drills, A chatbot suggests....
*********************************************
1. Tool Sharpening Services in Melbourne:
Melbourne Tool Sharpening
They specialize in sharpening drills, saw blades, and other cutting
tools. They offer services for both individual and industrial
customers.
Website: melbournetoolsharpening.com.au
Advanced Tooling Australia
This company provides sharpening for a wide range of tools, including
twist drills, and offers tool reconditioning services. They cater to
both large industries and individual customers.
Website: advancedtooling.com.au

2. Machine Shops and Industrial Services:
Melbourne Tool & Cutter Grinding

Specializes in sharpening and reconditioning various tools, including
drill bits. They are well-regarded in the area for high-quality
sharpening services.
Website: mtcgrinding.com.au
Drill Doctor Australia

Drill Doctor provides sharpening services for drills and other cutting
tools. They have a presence in Melbourne and offer professional
sharpening services for various types of drills.
Website: drilldoctor.com.au

3. Local Hardware Stores and Industrial Tool Suppliers:
Bunnings Warehouse (Tool Sharpening Services)

Some Bunnings stores offer tool sharpening services, including drill
bit sharpening. You can check with your local store for more
information.
Website: bunnings.com.au

Tool Fix
Tool Fix offers sharpening services for a range of power tools and
hand tools. They cater to both individuals and businesses.
Website: toolfix.com.au

4. Online Services (Mail-In Option):
Sharpening Services Australia
If you're open to mailing in your tools, Sharpening Services Australia
provides sharpening for drills and other tools. They offer a
convenient mail-in option.
Website: sharpeningservices.com.au

*****************************************

[Xeno]

Post by Trevor Wilson

Post by Sylvia Else

Post by Xeno

Post by Sylvia Else
Anyone had any success with these?
In a triumph of hope over experience, I bought a set of three Irwin
brand screw removal tools. These have a drill at one end, and the
spiral thread kind of cone at the other end.
My problem always seems to be drilling the initial hole. In this
case what I would take to be cheap self-tapping screws seem to be
made of diamond.
Sylvia.

The problem is that self tapping screws are harder and the first
problem you will encounter is the drill trying to run off the centre.
A simple jig may serve here to keep the drill central. The next issue
is the hardness of the drill relative to the hardness of the
extractor. The extractors are harder (M2 High Speed Steel) but they
may or may not be harder than the self tapping screw. It certainly
looks that way if you are describing them as made of diamond.
Will you have any material left if you drill out the centre? The next
stage (other end) is nothing more than the standard ezy out type
extractor meant to rotate in reverse - albeit a bit shorter. Most
self tappers I've used don't have a lot of meat inside the flutes to
even drill a hole into much less get an extractor in there.
BTW, Irwin brands are only so so quality. Might not be hard enough.

I'd be content to drill the head entirely off, then get a vice-grip
onto what's left. Even some cobalt drill bits were struggling to make
headway.
The heads themselves are nicely contoured to make gripping them
impossible. I tried to file some flats onto them, but that didn't work.
The available angle to approach is awkward anyway, and on one I
previously attacked, the bit was eventually slipping off the head
completely rather than drilling it any further.
Plan C involves an angle grinder.
Sylvia.

* If it is a small-ish screw, you could attack it with a Dremel™ fitted
with a grinding disk, so as to make a slot suitable for a flat blade
screwdriver. I've done this with lots of damaged Allen head screws.
* Make sure you have decent drills. There are plenty of really poor
quality drill bits available at Bunnings. There are a small number of

You ain't just whistling dixie! I bought a drill kit from Bunnings, an
assortment of bits of different sizes. First drill I tried out of the
box, maybe 3/16", just *bent* the moment it tried to drill the target
metal which was only mild steel. But, get this, it bent in the upper
flute area, an area that should be hardened and snap, not bend. And I
hadn't even begun to apply any pressure anyway. It went back to Bunnings
for a refund. I figured if one was faulty, the rest weren't worth taking
a chance on.

Post by Trevor Wilson
decent ones. Look for a genuine Aussie made one if you can. They
generally cost much more than the Chinese ones.

We used to use P&N and Suttons drills when teaching drill sharpening.
Used to get lots of *samples* direct from the factory. I think Suttons
now owns P&N but still operate in Thomastown.

[Trevor Wilson]

Post by Xeno

Post by Trevor Wilson

Post by Sylvia Else

Post by Xeno

Post by Sylvia Else
Anyone had any success with these?
In a triumph of hope over experience, I bought a set of three Irwin
brand screw removal tools. These have a drill at one end, and the
spiral thread kind of cone at the other end.
My problem always seems to be drilling the initial hole. In this
case what I would take to be cheap self-tapping screws seem to be
made of diamond.
Sylvia.

The problem is that self tapping screws are harder and the first
problem you will encounter is the drill trying to run off the
centre. A simple jig may serve here to keep the drill central. The
next issue is the hardness of the drill relative to the hardness of
the extractor. The extractors are harder (M2 High Speed Steel) but
they may or may not be harder than the self tapping screw. It
certainly looks that way if you are describing them as made of diamond.
Will you have any material left if you drill out the centre? The
next stage (other end) is nothing more than the standard ezy out
type extractor meant to rotate in reverse - albeit a bit shorter.
Most self tappers I've used don't have a lot of meat inside the
flutes to even drill a hole into much less get an extractor in there.
BTW, Irwin brands are only so so quality. Might not be hard enough.

I'd be content to drill the head entirely off, then get a vice-grip
onto what's left. Even some cobalt drill bits were struggling to make
headway.
The heads themselves are nicely contoured to make gripping them
impossible. I tried to file some flats onto them, but that didn't work.
The available angle to approach is awkward anyway, and on one I
previously attacked, the bit was eventually slipping off the head
completely rather than drilling it any further.
Plan C involves an angle grinder.
Sylvia.

* If it is a small-ish screw, you could attack it with a Dremel™
fitted with a grinding disk, so as to make a slot suitable for a flat
blade screwdriver. I've done this with lots of damaged Allen head screws.
* Make sure you have decent drills. There are plenty of really poor
quality drill bits available at Bunnings. There are a small number of

You ain't just whistling dixie! I bought a drill kit from Bunnings, an
assortment of bits of different sizes. First drill I tried out of the
box, maybe 3/16", just *bent* the moment it tried to drill the target
metal which was only mild steel. But, get this, it bent in the upper
flute area, an area that should be hardened and snap, not bend. And I
hadn't even begun to apply any pressure anyway. It went back to Bunnings
for a refund. I figured if one was faulty, the rest weren't worth taking
a chance on.

**I learned my lesson a few years back. I decided to shore up the
foundations of my home. As part of the process, I strengthened the
hardwood 100 X 100 bearers (the house was built in 1960), by securing a
piece of 9mm steel angle to the bottom and one side and another piece of
9mm steel flat to the other side of the bearer. I decided to use 13mm
gal bolts from side to side and top to bottom. I had to drill, maybe, 50
holes all up. So, the drill went through 9mm mid steel, then through
100mm of Aussie hardwood, then 9mm steel. After half a dozen holes, the
drill bit had no edge left. I went to Bunnings and spent 30 Bucks on an
Aussie made 13mm drill bit. Hot knife through butter. All 50-odd holes
took very little time. For day to day stuff, I have a set of Chinese
made P&N drills. They're fine for ordinary duty work, but for something
special, I look for the Aussie made drills.

FWIW: I very clearly recall Choice Magazine testing drill bits a few
years ago. They rejected a Frost branded, Chinese made set, on the basis
that one of the drills had the flutes running the wrong way!

Post by Xeno

Post by Trevor Wilson
decent ones. Look for a genuine Aussie made one if you can. They
generally cost much more than the Chinese ones.

We used to use P&N and Suttons drills when teaching drill sharpening.
Used to get lots of *samples* direct from the factory. I think Suttons
now owns P&N but still operate in Thomastown.

[Noddy]

Post by Trevor Wilson
**I learned my lesson a few years back. I decided to shore up the
foundations of my home. As part of the process, I strengthened the
hardwood 100 X 100 bearers (the house was built in 1960), by securing a
piece of 9mm steel angle to the bottom and one side and another piece of
9mm steel flat to the other side of the bearer. I decided to use 13mm
gal bolts from side to side and top to bottom. I had to drill, maybe, 50
holes all up. So, the drill went through 9mm mid steel, then through
100mm of Aussie hardwood, then 9mm steel. After half a dozen holes, the
drill bit had no edge left. I went to Bunnings and spent 30 Bucks on an
Aussie made 13mm drill bit. Hot knife through butter. All 50-odd holes
took very little time. For day to day stuff, I have a set of Chinese
made P&N drills. They're fine for ordinary duty work, but for something
special, I look for the Aussie made drills.

Just a couple of little pedants if I may :)

Firstly, very few poeple, if any, make 9mm angle. Common sizes are 3, 4,
5, 6, 8 and 10, 12 and 16mm. You probably just measured it wrong.

Secondly, The difference between a good and bad drill bit is not so much
where it comes from or the material that it's made from, but the cutting
edge put on the end of it. Over 90% of the world's twist drills are made
from High Speed Steel, otherwise known as "tool steel", and while there
are a number of different grades M2 (which is the lowest spec) is the
most common. There are higher grades which have things like higher
Cobolt content which make drills more durable in extreme applications,
but for the most part standard M2 twist drills are fine.

The thing that separates a durable drill from one that's not so durable
is the cutting edge ground into the head. cheaper drills tend to have
very basic "quick and dirty" cutting faces ground into them which make
them okay for softer materials, but for anything harder they don't tend
to last long because the edge goes away quickly. For more durable drills
different split chisel points, negative back rakes and different
clearance angles provide superior performance, but grinding drills to
these standards increases the complexity of the manufacturing process
which increases the price.

Short story is that if you can sharpen drills yourself then you don't
need to pay expensive prices for drill bits, as that's where the
difference lies.

[Keithr0]

Post by Trevor Wilson

Post by Sylvia Else

Post by Xeno

Post by Sylvia Else
Anyone had any success with these?
In a triumph of hope over experience, I bought a set of three Irwin
brand screw removal tools. These have a drill at one end, and the
spiral thread kind of cone at the other end.
My problem always seems to be drilling the initial hole. In this
case what I would take to be cheap self-tapping screws seem to be
made of diamond.
Sylvia.

The problem is that self tapping screws are harder and the first
problem you will encounter is the drill trying to run off the centre.
A simple jig may serve here to keep the drill central. The next issue
is the hardness of the drill relative to the hardness of the
extractor. The extractors are harder (M2 High Speed Steel) but they
may or may not be harder than the self tapping screw. It certainly
looks that way if you are describing them as made of diamond.
Will you have any material left if you drill out the centre? The next
stage (other end) is nothing more than the standard ezy out type
extractor meant to rotate in reverse - albeit a bit shorter. Most
self tappers I've used don't have a lot of meat inside the flutes to
even drill a hole into much less get an extractor in there.
BTW, Irwin brands are only so so quality. Might not be hard enough.

I'd be content to drill the head entirely off, then get a vice-grip
onto what's left. Even some cobalt drill bits were struggling to make
headway.
The heads themselves are nicely contoured to make gripping them
impossible. I tried to file some flats onto them, but that didn't work.
The available angle to approach is awkward anyway, and on one I
previously attacked, the bit was eventually slipping off the head
completely rather than drilling it any further.
Plan C involves an angle grinder.
Sylvia.

* If it is a small-ish screw, you could attack it with a Dremel™ fitted
with a grinding disk, so as to make a slot suitable for a flat blade
screwdriver. I've done this with lots of damaged Allen head screws.

That's a technique that I've used many times to remove rusted screws,
you can put more torque on a slot than a philips head.

Post by Trevor Wilson
* Make sure you have decent drills. There are plenty of really poor
quality drill bits available at Bunnings. There are a small number of
decent ones. Look for a genuine Aussie made one if you can. They
generally cost much more than the Chinese ones.