"Bill Woods" wrote in message
...
Do drill bits for use in ordinary "home use" drills get blunt with
the result that they work less well?

I ask this because I recently used my hammer drill to make some 6mm
holes in masonry in the concrete ceiling above me and it seemed like
very slow work. When I used a smaller drill bit of about 4 to 5 mm
in the same masonry material then it was much, much easier to make
the hole. I used a vaccum cleaner to suck up particles and to
prevent the bit clogging with concrete dust.

Of course the smaller bit makes a hole with a smaller area but the
difference seemed far greater than this. I wonder if my 6mm drill
bit (and maybe others) need replacing?

This is the type of drill bit I used:
http://www.tool-up.co.uk/tooldev/images/items/24343.jpg
http://www.tool-up.co.uk/tooldev/images/items/9487.jpg

those don't look like very good quality, rather than sharpen them, go and
buy a real drill and bits, a good quality sds drill at about 100 pounds and
some sds bits to go with it, I have found practically no difference in
quality between cheap and expensive sds bits (ymmv) but the actual electric
drill quality varies a bit, the cheapy heavy sds from the sheds works great
but only if you are strong, a good quality bosch or aeg drill is much nicer
though.

mrcheerful

Bill Woods wrote:
Do drill bits for use in ordinary "home use" drills get blunt with
the result that they work less well?

Yes. You can sharpen them with a grinder, though. *Don't* quench the
bits after grinding, let them cool slowly.

mrcheerful . wrote:
"Bill Woods" wrote in message
...

Do drill bits for use in ordinary "home use" drills get blunt with
the result that they work less well?

I ask this because I recently used my hammer drill to make some 6mm
holes in masonry in the concrete ceiling above me and it seemed like
very slow work. When I used a smaller drill bit of about 4 to 5 mm
in the same masonry material then it was much, much easier to make
the hole. I used a vaccum cleaner to suck up particles and to
prevent the bit clogging with concrete dust.

Of course the smaller bit makes a hole with a smaller area but the
difference seemed far greater than this. I wonder if my 6mm drill
bit (and maybe others) need replacing?

This is the type of drill bit I used:
http://www.tool-up.co.uk/tooldev/images/items/24343.jpg
http://www.tool-up.co.uk/tooldev/images/items/9487.jpg


those don't look like very good quality, rather than sharpen them, go and
buy a real drill and bits, a good quality sds drill at about 100 pounds and
some sds bits to go with it, I have found practically no difference in
quality between cheap and expensive sds bits (ymmv) but the actual electric
drill quality varies a bit, the cheapy heavy sds from the sheds works great
but only if you are strong, a good quality bosch or aeg drill is much nicer
though.

mrcheerful

This sort of reply is probably what I find most annoying about this
otherwise excellent uk.d-i-y group. Someone comes and asks whether a
masonry drill can get blunt, and the reply he gets is "That looks a poor
quality bit - buy a £100 drill and new bits, although cheap bits make
little difference."

So, now, rather than looking at £10+ for new bits, he's looking at £100+
for a new drill AND new bits.

Whilst I agree that a good drill is, well, good, many people cannot
justify spending that sort of money on tools. In my case, I cannot
afford to get people in to do the work, and therefore I cannot also
afford to spent large sums of money on quality tools and have to live
with a £25 SDS drills from Argos which weighs a ton, but only comes out
maybe 3 times a year, and a £30 compound mitre saw from B&Q which did my
dado and stair spindles wonderfully.

Anyway - to get back to the point (no pun intended) - I do find that
masonry bits do get blunt - and I just buy a new one every so often (
£1 at Screwfix for small bits I think)

D

On Fri, 13 May 2005 10:41:36 +0100, David Hearn
wrote:

the reply he gets is "That looks a poor
quality bit - buy a £100 drill and new bits, although cheap bits make
little difference."

It's good advice. if you have a house to maintain, money on an SDS drill
isn't going to be wasted.

By the nature of SDS drills, they're also much less susceptible to the
effects of blunted drillbits.

--
Cats have nine lives, which is why they rarely post to Usenet.

On Fri, 13 May 2005 09:43:31 +0100, Bill Woods
wrote:

Do drill bits for use in ordinary "home use" drills get blunt with
the result that they work less well?

Decent quality tungsten carbide masonry drills for "home use" should
maintain an edge for longer than it takes for you to lose them. Maybe if
you're in a granite or blue brick house and doing a lot of work you'll
wear them out, but for "average" use this just shouldn't be an issue.

Be aware that not all drills with a brazed-in insert use carbide. The
market stall crap is now just that - crap. If your drill bits are
wearing out, get better drills.

You have little chance of sharpening them, although it's easy to do
(much easier than a bit for metal). The right abrasive to do it will
cost you more than several year's supply of drills. Although you can
easily sharpen the non-carbide inserts, it's not worth it.

And get an SDS drill. You won't look back afterwards.

--
Cats have nine lives, which is why they rarely post to Usenet.

Andy Dingley wrote:
On Fri, 13 May 2005 09:43:31 +0100, Bill Woods
wrote:

Do drill bits for use in ordinary "home use" drills get blunt with
the result that they work less well?

Decent quality tungsten carbide masonry drills for "home use" should
maintain an edge for longer than it takes for you to lose them. Maybe
if
you're in a granite or blue brick house and doing a lot of work
you'll
wear them out, but for "average" use this just shouldn't be an issue.

Be aware that not all drills with a brazed-in insert use carbide. The
market stall crap is now just that - crap. If your drill bits are
wearing out, get better drills.

You have little chance of sharpening them, although it's easy to do
(much easier than a bit for metal). The right abrasive to do it will
cost you more than several year's supply of drills. Although you can
easily sharpen the non-carbide inserts, it's not worth it.


This is going back a bit, but does anyone know if Plasplugs brand
masonry bits (assuming they still exist) still include the offer on the
packet to send them back for re-sharpening at =A31 a time?

MBQ

I ask this because I recently used my hammer drill to make some 6mm
holes in masonry in the concrete ceiling above me and it seemed like
very slow work. When I used a smaller drill bit of about 4 to 5 mm
in the same masonry material then it was much, much easier to make
the hole. I used a vaccum cleaner to suck up particles and to
prevent the bit clogging with concrete dust.

Of course the smaller bit makes a hole with a smaller area but the
difference seemed far greater than this. I wonder if my 6mm drill
bit (and maybe others) need replacing?

This is the type of drill bit I used:
http://www.tool-up.co.uk/tooldev/images/items/24343.jpg
http://www.tool-up.co.uk/tooldev/images/items/9487.jpg


those don't look like very good quality, rather than sharpen them, go and
buy a real drill and bits, a good quality sds drill at about 100 pounds
and some sds bits to go with it, I have found practically no difference
in quality between cheap and expensive sds bits (ymmv) but the actual
electric drill quality varies a bit, the cheapy heavy sds from the sheds
works great but only if you are strong, a good quality bosch or aeg drill
is much nicer though.

mrcheerful

This sort of reply is probably what I find most annoying about this
otherwise excellent uk.d-i-y group. Someone comes and asks whether a
masonry drill can get blunt, and the reply he gets is "That looks a poor
quality bit - buy a £100 drill and new bits, although cheap bits make
little difference."

So, now, rather than looking at £10+ for new bits, he's looking at £100+
for a new drill AND new bits.

Whilst I agree that a good drill is, well, good, many people cannot
justify spending that sort of money on tools. In my case, I cannot afford
to get people in to do the work, and therefore I cannot also afford to
spent large sums of money on quality tools and have to live with a £25 SDS
drills from Argos which weighs a ton, but only comes out maybe 3 times a
year, and a £30 compound mitre saw from B&Q which did my dado and stair
spindles wonderfully.

Anyway - to get back to the point (no pun intended) - I do find that
masonry bits do get blunt - and I just buy a new one every so often ( £1
at Screwfix for small bits I think)

D

saying yes you can sharpen them won't actually help in the long run, I
believe. using Mickey mouse drill bits is likely to lead to frustration and
possible injury.
some cheapy tools are great, others are a waste of space.

my wicks percussion drill seemed a big expenditure in the early 80's (55
pounds from memory), but it is still working perfectly and I have never worn
out a drill bit!, how many black and Decker hammer drills and bits would I
have thrown away in that time? Also bear in mind that I work for other
people to some extent, so it gets light trade use! I also have a 26 pound
pp sds drill (also 26 pounds in weight !), which I lend out.

mrcheerful

David Hearn wrote:

This sort of reply is probably what I find most annoying about this
otherwise excellent uk.d-i-y group. Someone comes and asks whether a
masonry drill can get blunt, and the reply he gets is "That looks a poor
quality bit - buy a £100 drill and new bits, although cheap bits make
little difference."

You seem to be misquoting there...

The "cheap bits make little difference" part is *only* applicable to SDS
bits. This is not the case with conventional masonry bits.

--
Cheers,

John.

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\================================================= ================/

Hi Bill
Do drill bits for use in ordinary "home use" drills get blunt with
the result that they work less well?

Yes they do, how fast depends on what you are drilling. My 50's built house
has cement render on the internal walls. Masonry nails bend if you try to
hammer them in. I destroyed 4 x 6mm drill bits putting in new skirting &
dado rails in a 30' x 15' room.

Dave

Bill Woods wrote:

Do drill bits for use in ordinary "home use" drills get blunt with
the result that they work less well?

Yes.

I ask this because I recently used my hammer drill to make some 6mm
holes in masonry in the concrete ceiling above me and it seemed like
very slow work. When I used a smaller drill bit of about 4 to 5 mm
in the same masonry material then it was much, much easier to make

Of course the smaller bit makes a hole with a smaller area but the
difference seemed far greater than this. I wonder if my 6mm drill
bit (and maybe others) need replacing?

As you note a smaller hole will always be quicker to make anyway - even
if the 5 and 6mm bits were equally sharp. You could also consider
"opening up" a smaller hole by drilling it with the smaller sharp bit,
and then redrilling with the larger bit.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote:
David Hearn wrote:

This sort of reply is probably what I find most annoying about this
otherwise excellent uk.d-i-y group. Someone comes and asks whether a
masonry drill can get blunt, and the reply he gets is "That looks a
poor quality bit - buy a £100 drill and new bits, although cheap bits
make little difference."


You seem to be misquoting there...

The "cheap bits make little difference" part is *only* applicable to SDS
bits. This is not the case with conventional masonry bits.


Sorry, I failed to notice that point. I've certainly had some cheap
masonry bits which actually untwisted (or twisted up - can't remember
exactly) when used! The result was a completely straight piece of metal!

As for the other comments - I don't deny that over someone's lifetime
(or more importantly, the lifetime of the tool) that spending money on a
good tool isn't actually that expensive and may be the cheapest option -
however I'm sure I'm not the only one where money is tight, and whilst
you may spend more over your lifetime buying replacement tools - its the
short term spend which is the most important. Same with our mortgage -
we opted for 30 years over 25 as it made a sizeable difference to the
monthly outgoing. If you look at the extra interest paid over the
lifetime of the loan it's shocking - but £50 per month saving in the
short term is important to us (5 years out of Uni, living in Surrey with
wife and kid).

D

John Rumm wrote:
As you note a smaller hole will always be quicker to make anyway - even
if the 5 and 6mm bits were equally sharp. You could also consider
"opening up" a smaller hole by drilling it with the smaller sharp bit,
and then redrilling with the larger bit.

..... although without care this is likely to result in the TC tip
shearing off.

On Fri, 13 May 2005 09:43:31 +0100, Bill Woods
wrote:

Do drill bits for use in ordinary "home use" drills get blunt with
the result that they work less well?

Yes, and very Yes when it happens to me.




I ask this because I recently used my hammer drill to make some 6mm
holes in masonry in the concrete ceiling above me and it seemed like
very slow work. When I used a smaller drill bit of about 4 to 5 mm
in the same masonry material then it was much, much easier to make
the hole. I used a vaccum cleaner to suck up particles and to
prevent the bit clogging with concrete dust.

Of course the smaller bit makes a hole with a smaller area but the
difference seemed far greater than this. I wonder if my 6mm drill
bit (and maybe others) need replacing?

This is the type of drill bit I used:
http://www.tool-up.co.uk/tooldev/images/items/24343.jpg
http://www.tool-up.co.uk/tooldev/images/items/9487.jpg


later,

tom @ www.CarFleaMarket.com

David Hearn wrote:

You seem to be misquoting there...

The "cheap bits make little difference" part is *only* applicable to
SDS bits. This is not the case with conventional masonry bits.


Sorry, I failed to notice that point. I've certainly had some cheap
masonry bits which actually untwisted (or twisted up - can't remember
exactly) when used! The result was a completely straight piece of metal!

Yup, I know the type of thing ;-)

As in the other reply, I have certainly found bits like you describe -
although not as yet SDS ones. So far all of those seem to be at least
adequate.

As for the other comments - I don't deny that over someone's lifetime
(or more importantly, the lifetime of the tool) that spending money on a
good tool isn't actually that expensive and may be the cheapest option -
however I'm sure I'm not the only one where money is tight, and whilst
you may spend more over your lifetime buying replacement tools - its the
short term spend which is the most important. Same with our mortgage -

I was not commenting on that part of your response as such - only the
bit about the bits themselves.

We went through many of the cost Vs quality discussions when writing the
power tool section for the FAQ - I hope we have at least got a cross
section of most points of view on this.

http://www.diyfaq.org.uk/powertools/index.htm

The important point however (IMHO for masonry drilling) is using an SDS
drill rather than a hammer one. Most folks who have used ones tend to be
pretty evangelical about them since they are just *so* much better at
the job!

--
Cheers,

John.

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\================================================= ================/

Chris Bacon wrote:

even if the 5 and 6mm bits were equally sharp. You could also consider
"opening up" a smaller hole by drilling it with the smaller sharp bit,
and then redrilling with the larger bit.


.... although without care this is likely to result in the TC tip
shearing off.

if the drill is knackered anyway there is not much to lose though ;-)


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"Bill Woods" wrote in message
...
Do drill bits for use in ordinary "home use" drills get blunt with
the result that they work less well?

Absolutely.


I ask this because I recently used my hammer drill to make some 6mm
holes in masonry in the concrete ceiling above me and it seemed like
very slow work. When I used a smaller drill bit of about 4 to 5 mm
in the same masonry material then it was much, much easier to make
the hole. I used a vaccum cleaner to suck up particles and to
prevent the bit clogging with concrete dust.

Sometimes you will hit rebar or aggregate. Go slow so you can stop before
you smoke a bit. For a piece of aggregate, I use a round pin that comes in
a wrought iron gate spring kit. It is cold rolled steel, and won't bend. I
grind a point on it, and stick it in the hole to break the piece of
aggregate. If it is rebar, you will know it by the feel when you hit it.
BTW, pulling the drill out occasionally, and letting the cuttings fly away
is a good idea.


Of course the smaller bit makes a hole with a smaller area but the
difference seemed far greater than this. I wonder if my 6mm drill
bit (and maybe others) need replacing?

Unless you do this for a living, just buy run of the mill bits, and visually
check them during use. Hold a new good one next to a questionable one. If
it is shredded, you will SEE the problem. If it looks much like the new
one, you are hitting something in the hole. Masonry bits are more forgiving
than regular bits, and sharpening them isn't as exacting. I have a Drill
Doctor, but as yet haven't sharpened one bit on it, masonry or regular.


This is the type of drill bit I used:
http://www.tool-up.co.uk/tooldev/images/items/24343.jpg
http://www.tool-up.co.uk/tooldev/images/items/9487.jpg

Like I say, if you are going to be doing this a lot, you might want to spend
the $200 US for a rotohammer and some bits. If only a weekend warrior, any
old hammer drill and bit will do it, just not as fast. The larger drill
bits may take longer depending on the sack mix of your original concrete.

On Fri, 13 May 2005 10:41:36 +0100, David Hearn
wrote:


This sort of reply is probably what I find most annoying about this
otherwise excellent uk.d-i-y group. Someone comes and asks whether a
masonry drill can get blunt, and the reply he gets is "That looks a poor
quality bit - buy a £100 drill and new bits, although cheap bits make
little difference."

My reply was simple ant to the point!

sponix

Do drill bits for use in ordinary "home use" drills get blunt with
the result that they work less well?

What you picture is a masonry bit, NOT a hammer drill bit.
Yes, that type will get blunt as they are not made to take the pounding from
the hammer drill.

It looks like you have 2 choices: use the cheap things and when theyre
shot, toss them or buy the proper type which will last.
I had 12 - 3" X 1/2" holes to drill in a foundation and used the same type
of bit in your picture. Used a 3/8 VSR drill and when I was done, the bit
was thrashed but it did the job. It did take a lot of grunt work to get them
done !

Later I had to drill another dozen or so of the same holes in another
section (for driveway rebar).
I rented a BOSCH hammer drill and they included the bit. Probably took 1/3
the time and the bit did the grunt work this time.

Like almost anything else, many tools can be used to do a job but the proper
tool will do the best job (but will probably cost more..but will last
longer)


Saw this sign in a workshop:

EVERY TOOL HAS ITS PROPER USE.

It was framed on a board and attached to the wall by having a screwdriver
driven through the frame G

R

In article ,
Bill Woods wrote:
Do drill bits for use in ordinary "home use" drills get blunt with
the result that they work less well?

Yes - and it's easily seen if you have good eyesight or use a magnifying
glass, the cutting edge gets rounded off. Compare with a new one.

--
*Young at heart -- slightly older in other places

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

In article ,
mrcheerful
. wrote:
my wicks percussion drill seemed a big expenditure in the early 80's (55
pounds from memory), but it is still working perfectly and I have never
worn out a drill bit!, how many black and Decker hammer drills and bits
would I have thrown away in that time? Also bear in mind that I work
for other people to some extent, so it gets light trade use! I also
have a 26 pound pp sds drill (also 26 pounds in weight !), which I lend
out.

I well remember the frustration of trying to drill into concrete ceilings
with a hammer drill. It's just damn near impossible if it's half decent
concrete. The answer is quite simply SDS. With the prices now so low you
don't need to wreck many ordinary masonry drills to pay for one. And as
you say, the SDS bits tend to last for ever.

--
*I wished the buck stopped here, as I could use a few.

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

In article ,
wrote:

It's just common sense.

So is posting the right way up and trimming to context, but you seem unabe
to grasp that.


--
AJL Electronics (G6FGO) Ltd : Satellite and TV aerial systems
http://www.classicmicrocars.co.uk : http://www.ajlelectronics.co.uk

** Would you like to learn to post effectively? **
** http://www.allmyfaqs.com/faq.pl?How_to_post **

On Fri, 13 May 2005 09:43:31 +0100, Bill Woods
wrote:

Do drill bits for use in ordinary "home use" drills get blunt with
the result that they work less well?


Yes

Rick

So is posting the right way up and trimming to context, but you seem unabe
to grasp that.

It's nice to live in a perfect world, isn't it? Where everything goes
according to plan, where you don't have to figure things out, and where
everyone does it YOUR way.

Welcome to reality, pal.

Steve

Bill Woods wrote:

I don't understand.

What is the difference between a masonry bit and a bit for a
hammer drill?

(I do not think you are referring to SDS.)

Yup, I am not sure what he means either....


--
Cheers,

John.

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\================================================= ================/

I don't understand.
What is the difference between a masonry bit and a bit for a
hammer drill?
(I do not think you are referring to SDS.) Yes, I am

Rudy wrote:

Yes, I am

This is probably a country specific terminology thing then...

(I take it you are not in the UK?)

In UK terminology, the masonry bit pictured by the OP would be used in a
conventional "hammer drill", but not a "SDS Drill", or "Rotary Hammer".



--
Cheers,

John.

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\================================================= ================/