I recently drilled some holes in the cast iron top of my saw to install
a new fence. When I was done, the tip of the drill bit was too dull to
drill soft pine. (When I first tried using the bit on wood, I thought
the drill was running in reverse).
Anyway, I figured that that with a little metal working knowledge I
might be able to drill more than four holes before completely dulling a
bit. Maybe it was the wrong type of bit? (It was from a dewalt set with
a yellow/gold coating).
Can anyone recommend a basic metalworking book so I could read up on
the right technique for this a future metalworking endeavors?.
Hopefully it will include a chapter on sharpening drill bits too.
Thanks
Mitch
Joe AutoDrill wrote:
>>>Again, see http://www.multi-drill.com/drill-speed-chart.htm
>>
>>Interesting. Is brass so fast because that (*hoping*) keeps it from
>>grabbing the workpiece?
>
>
> Hoping as in wishing for good results?
>
> Bottom line is that it generally works like aluminum unless you are working
> with an machine such as CNC that maximizes thrust, RPM, etc. Not exactly
> like aluminum of course, but close enough that for the general purpose end
> user, the speeds posted should work just fine.
>
> ...It is almost always necessary to use some sort of lubricant with aluminum
> though as it sticks in the flutes real bad once the bit is hot... Might be
> the same problem with brass or some bronze alloys depending on how
> aggressive you are. Alumibronze is usually okay because it is hard but I
> don't have too much experience with the real soft stuff.
My experience is rather limited, but says the bit edge digs in to the
brass far more readily than it does in aluminum.
There are special bits for brass, though, (less rake to the edge) that
are supposed to mitigate this.
er
--
email not valid
Sat, Feb 4, 2006, 3:29pm (EST-3) [email protected] (MB) mumbles:
<snip> Can anyone recommend a basic metalworking book <snip>
Basic. You want info on wood, you come here. You want info on
metal, you best check with a metal newsgroup.
JOAT
Have a nice day!
Someplace else.
Try starting out with a 1/8" bit and gradually work your way up to the size
you need in 1/8" increments. I'd stay away from using water for cooling it
doesn't go well with cast iron, instead use cutting oil. It can be had at
most hardware stores. 3-in-1 oil works well too. As one other poster said,
make sure you have sharp bits and use twist drills. Cast iron is brittle and
can have imperfections in the casting so be prepared to break a couple bits
in the process.
"MB" <[email protected]> wrote in message
news:[email protected]...
>I recently drilled some holes in the cast iron top of my saw to install
> a new fence. When I was done, the tip of the drill bit was too dull to
> drill soft pine. (When I first tried using the bit on wood, I thought
> the drill was running in reverse).
>
> Anyway, I figured that that with a little metal working knowledge I
> might be able to drill more than four holes before completely dulling a
> bit. Maybe it was the wrong type of bit? (It was from a dewalt set with
> a yellow/gold coating).
>
> Can anyone recommend a basic metalworking book so I could read up on
> the right technique for this a future metalworking endeavors?.
> Hopefully it will include a chapter on sharpening drill bits too.
>
> Thanks
>
> Mitch
>
> You were probably running the drill much too fast and not using
> coolant...
No coolant is needed on Cast Iron if you run it at approxmately 75% or less
of the maximum suggested RPM...
Again, see http://www.multi-drill.com/drill-speed-chart.htm
--
Regards,
Joe Agro, Jr.
(800) 871-5022
(908) 542-0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com
V8013-R
There is no such thing as to slow. To fast is a different story. The speeds
listed in the link are WAY to fast and will guarantee a burned up drill bit.
Cast iron drills quite nicely with the proper technique. Drilling by hand
with a drill motor in metal is quite hard on a drill bit. It cannot be fed
fast enough for an efficient cut. It does a lot of scraping rather than
cutting. This dulls the point rapidly.
<[email protected]> wrote in message
news:[email protected]...
> You'll burn up a small drill bit at slow speed. Cast iron can be a
> real BITCH to drill, too. Use brad point bits on wood and twist drills
> on metal.
>
MB wrote:
> Anyway, I figured that that with a little metal working knowledge
> I might be able to drill more than four holes before completely
> dulling a bit.
I'm no metalworker, but I've had the same problem. Seems to me, every
machine shop I've ever seen uses plenty of water and coolant sprayed
on the cutter. When drilling metal I've found it quite beneficial to
use a sharp drill and either run a small stream of water where the bit
meets the metal, or find a way to pool the water at the drilling
location. It would appear that metal cutting metal generates an awful
lot of heat... enough to heat up the sharp edge of a drill bit and
temper it's hardness.... thus making it duller... thus generating more
heat... etc.
Like I said, I'm no machinist, but those have been my experiences and
keeping a sharp bit doused in water helps an awful lot.
Joe Barta
> Here's a speed chart.
> http://www.ibiblio.org/twa/info/drillSpeedChart.pdf
Ick...
Hmm... Is posting my own link in three posts - in a row obnoxious?
LOL... http://www.multi-drill.com/drill-speed-chart.htm
See my chart. See MY chart. That site's info will kill your tools.
Heck... e-mail me and I'll do the research for you... Just don't use that
first chart!
> You'll burn up a small drill bit at slow speed. Cast iron can be a
> real BITCH to drill, too. Use brad point bits on wood and twist drills
> on metal.
Cast Iron is actually one of the easier metals to drill because it "flakes"
out rather than creating sticky chips...
I wood terms... Cast Iron is to Oak as Aluminum is to Sappy Pine...
> Also ask over on the rec.crafts.metalworking newsgroup. There are guys
> there with 'bout 100 years of experience. (Right, Andy?) <g>
Yup. Good advice.
--
Regards,
Joe Agro, Jr.
(800) 871-5022
(908) 542-0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com
V8013-R
"MB" <[email protected]> wrote in message
news:[email protected]...
>I recently drilled some holes in the cast iron top of my saw to install
> a new fence. When I was done, the tip of the drill bit was too dull to
> drill soft pine. (When I first tried using the bit on wood, I thought
> the drill was running in reverse).
>
> Anyway, I figured that that with a little metal working knowledge I
> might be able to drill more than four holes before completely dulling a
> bit. Maybe it was the wrong type of bit? (It was from a dewalt set with
> a yellow/gold coating).
>
> Can anyone recommend a basic metalworking book so I could read up on
> the right technique for this a future metalworking endeavors?.
> Hopefully it will include a chapter on sharpening drill bits too.
There are a bunch of GREAT web sites which cost less than the book... But
it sounds like you ran too high an RPM. See the following next time...
http://www.multi-drill.com/drill-speed-chart.htm
It is a very conservative chart we put together. You probably can't ruin a
bit without trying at the speeds and sizes shown.
--
Regards,
Joe Agro, Jr.
(800) 871-5022
(908) 542-0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com
V8013-R
On 4 Feb 2006 15:29:29 -0800, with neither quill nor qualm, "MB"
<[email protected]> quickly quoth:
>I recently drilled some holes in the cast iron top of my saw to install
>a new fence. When I was done, the tip of the drill bit was too dull to
>drill soft pine. (When I first tried using the bit on wood, I thought
>the drill was running in reverse).
>
>Anyway, I figured that that with a little metal working knowledge I
>might be able to drill more than four holes before completely dulling a
>bit. Maybe it was the wrong type of bit? (It was from a dewalt set with
>a yellow/gold coating).
Here's a speed chart.
http://www.ibiblio.org/twa/info/drillSpeedChart.pdf
You'll burn up a small drill bit at slow speed. Cast iron can be a
real BITCH to drill, too. Use brad point bits on wood and twist drills
on metal.
>Can anyone recommend a basic metalworking book so I could read up on
>the right technique for this a future metalworking endeavors?.
>Hopefully it will include a chapter on sharpening drill bits too.
Also ask over on the rec.crafts.metalworking newsgroup. There are guys
there with 'bout 100 years of experience. (Right, Andy?) <g>
Sharpening almost all woodworking tools: Leonard Lee's book:
<http://www.amazon.com/gp/product/1561581259/ref=nosim/102-0554864-4657760?camp=2025&dev-t=D26XECQVNV6NDQ&link%5Fcode=xm2&n=283155>
---------------------------------------------------
I drive way too fast to worry about my cholesterol.
---------------------------------------------------
http://www.diversify.com Refreshing Graphic Design
> My experience is rather limited, but says the bit edge digs in to the
> brass far more readily than it does in aluminum.
>
> There are special bits for brass, though, (less rake to the edge) that
> are supposed to mitigate this.
You are correct in saying that there are special tools offered for this...
However, a single set of High Speed Steel (HSS) bits will work on just about
any metal you need to drill including the infamous Stainless Steel. The key
is to always run slower than the charts say and use coolant whenever
possible. Stainless can NOT be drilled without coolant unless you spiun the
bit at insanely low RPM rates. Of course, there are people who need to run
at the maximum possible RPM rate. They use Cobalt coated tooling, carbide
tooling, lots of specialized coolant, etc.
If anyone has a question as to what speed they need to run when drillign
metal, just shoot me an e-mail. It is part of what I do all day long for my
customers... A 10 second answer will not kill me and will probably save you
from buying a new tool.
In return, I'll ask all sorts of random and funky wood and wood-related
questions from time to time. :)
Regards,
Joe Agro, Jr.
(800) 871-5022
(908) 542-0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com
Joe AutoDrill (in _oPFf.3098$PK2.1846@trndny06) said:
| See the following next time...
|
| http://www.multi-drill.com/drill-speed-chart.htm
|
| It is a very conservative chart we put together. You probably
| can't ruin a bit without trying at the speeds and sizes shown.
Bookmarked. S'bout time. :-)
Thanks!
--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto
Get yourself a "Drill Doctor" unit to resharpen your twist bits.
The rec.crafts.metalworking group will amaze you with how complex an
issue drilling a hole can be to a machinist. Warning: their toys can be
*very* expensive!
J.
MB wrote:
> I recently drilled some holes in the cast iron top of my saw to install
> a new fence. When I was done, the tip of the drill bit was too dull to
> drill soft pine. (When I first tried using the bit on wood, I thought
> the drill was running in reverse).
>
> Anyway, I figured that that with a little metal working knowledge I
> might be able to drill more than four holes before completely dulling a
> bit. Maybe it was the wrong type of bit? (It was from a dewalt set with
> a yellow/gold coating).
>
> Can anyone recommend a basic metalworking book so I could read up on
> the right technique for this a future metalworking endeavors?.
> Hopefully it will include a chapter on sharpening drill bits too.
>
> Thanks
>
> Mitch
>
Thanks Joe for posting a realistic speed chart. That other one has been
around a while and makes me wonder how many drills have died due to it.
"Joe AutoDrill" <[email protected]> wrote in message
news:XtPFf.1740$VX2.690@trndny04...
> > Here's a speed chart.
> > http://www.ibiblio.org/twa/info/drillSpeedChart.pdf
>
> Ick...
>
> Hmm... Is posting my own link in three posts - in a row obnoxious?
>
> LOL... http://www.multi-drill.com/drill-speed-chart.htm
>
> See my chart. See MY chart. That site's info will kill your tools.
>
> Heck... e-mail me and I'll do the research for you... Just don't use
that
> first chart!
>
> > You'll burn up a small drill bit at slow speed. Cast iron can be a
> > real BITCH to drill, too. Use brad point bits on wood and twist drills
> > on metal.
>
> Cast Iron is actually one of the easier metals to drill because it
"flakes"
> out rather than creating sticky chips...
>
> I wood terms... Cast Iron is to Oak as Aluminum is to Sappy Pine...
>
> > Also ask over on the rec.crafts.metalworking newsgroup. There are guys
> > there with 'bout 100 years of experience. (Right, Andy?) <g>
>
> Yup. Good advice.
>
> --
>
>
> Regards,
> Joe Agro, Jr.
> (800) 871-5022
> (908) 542-0244
> Automatic / Pneumatic Drills: http://www.AutoDrill.com
> Multiple Spindle Drills: http://www.Multi-Drill.com
>
> V8013-R
>
>
>
On Mon, 06 Feb 2006 15:52:35 -0800, with neither quill nor qualm,
Enoch Root <[email protected]> quickly quoth:
>[email protected] wrote:
>
>> Also ask over on the rec.crafts.metalworking newsgroup. There are guys
>> there with 'bout 100 years of experience. (Right, Andy?) <g>
>
>If only they wouldn't incessantly natter off-topic. They make this
>group look positively *focused*!
>
>;-o
<bseg> Yeah, I'm hitting the (I)gnore key quite often there, too.
Believe it or not, there's even an OT topic discussing how many
fewer spams they're receiving lately. <thud>
--
DON'T VOTE. IT ONLY ENCOURAGES THEM!
MB (in [email protected]) said:
| I recently drilled some holes in the cast iron top of my saw to
| install a new fence. When I was done, the tip of the drill bit was
| too dull to drill soft pine. (When I first tried using the bit on
| wood, I thought the drill was running in reverse).
You were probably running the drill much too fast and not using
coolant...
| Anyway, I figured that that with a little metal working knowledge I
| might be able to drill more than four holes before completely
| dulling a bit. Maybe it was the wrong type of bit? (It was from a
| dewalt set with a yellow/gold coating).
If it was a twist drill, you were at least fairly close.
| Can anyone recommend a basic metalworking book so I could read up on
| the right technique for this a future metalworking endeavors?.
| Hopefully it will include a chapter on sharpening drill bits too.
Try news:rec.crafts.metalworking (you might first do a Google group
search and read the previous answers to the question before you ask it
again) and your local library.
--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto
[email protected] wrote:
> Also ask over on the rec.crafts.metalworking newsgroup. There are guys
> there with 'bout 100 years of experience. (Right, Andy?) <g>
If only they wouldn't incessantly natter off-topic. They make this
group look positively *focused*!
;-o
er
--
email not valid
>> Again, see http://www.multi-drill.com/drill-speed-chart.htm
>
> Interesting. Is brass so fast because that (*hoping*) keeps it from
> grabbing the workpiece?
Hoping as in wishing for good results?
Bottom line is that it generally works like aluminum unless you are working
with an machine such as CNC that maximizes thrust, RPM, etc. Not exactly
like aluminum of course, but close enough that for the general purpose end
user, the speeds posted should work just fine.
...It is almost always necessary to use some sort of lubricant with aluminum
though as it sticks in the flutes real bad once the bit is hot... Might be
the same problem with brass or some bronze alloys depending on how
aggressive you are. Alumibronze is usually okay because it is hard but I
don't have too much experience with the real soft stuff.
--
Regards,
Joe Agro, Jr.
(800) 871-5022
(908) 542-0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com
V8013-R