🚀 go-pugleaf

In article <jtmnb0$ovi$1@dont-email.me>,
   D. T. Green <greendt@mail.invalid> wrote:
> Have a small electric drill with a 8mm drill trying to drill through
> some mild steel about 7 mm thick.

> The drill is pretty blunt. I'm leaning on it and making little progress.

Sharpen it? Not too difficult to improve a blunt drill in a size as big as
this. A small oil stone, etc, will do it.  

> I know the answer is to travel out and buy another drill, but out of 
> interest; that so called 'milk' used on lathes (mixture of oil and water i 
> believe) would that help me in this situation?

> One aspect is that the drill is so hot, i'm wondering if all the temper 
> could be taken out of it, without some coolent? 

That is a primary reason for the cutting fluid. To keep things cool.

Also most mains electric drills will run too fast for this - which speeds
up the drill getting blunt.

-- 
*The sooner you fall behind, the more time you'll have to catch up *

    Dave Plowman        dave@davenoise.co.uk           London SW
                  To e-mail, change noise into sound.

On 12/07/2012 15:35, D. T. Green wrote:
> Have a small electric drill with a 8mm drill trying to drill through some
> mild steel about 7 mm thick.
>
> The drill is pretty blunt. I'm leaning on it and making little progress.
>
> I know the answer is to travel out and buy another drill, but out of
> interest; that so called 'milk' used on lathes (mixture of oil and water i
> believe) would that help me in this situation?
>
> One aspect is that the drill is so hot, i'm wondering if all the temper
> could be taken out of it, without some coolent?
>
>
Just about any lubricant would have helped before the drill bit was 
blunt....

On 12/07/2012 15:35, D. T. Green wrote:
> Have a small electric drill with a 8mm drill trying to drill through some
> mild steel about 7 mm thick.
>
> The drill is pretty blunt. I'm leaning on it and making little progress.
>
> I know the answer is to travel out and buy another drill, but out of
> interest; that so called 'milk' used on lathes (mixture of oil and water i
> believe) would that help me in this situation?
>
> One aspect is that the drill is so hot, i'm wondering if all the temper
> could be taken out of it, without some coolent?
>
>

A pilot drill of a few mm might make things easier.

Any fluid will help to keep the drill cool, from oil to water.

On 12/07/2012 15:35, D. T. Green wrote:
> Have a small electric drill with a 8mm drill trying to drill through some
> mild steel about 7 mm thick.
>
> The drill is pretty blunt. I'm leaning on it and making little progress.
>
> I know the answer is to travel out and buy another drill, but out of
> interest; that so called 'milk' used on lathes (mixture of oil and water i
> believe) would that help me in this situation?
>
> One aspect is that the drill is so hot, i'm wondering if all the temper
> could be taken out of it, without some coolent?
>
>
The milk is water based coolant ... not that good as an aid to cutting, 
other than it keeps the work/tool cool.

If you are drilling MS better to use a cutting fluid ... I keep a bottle 
of MWF Molyslip cutting fluid by drill press for most things ...
http://www.cromwell.co.uk/MLY7034550R
except aluminum when I use white spirit.

If your drill is blunt ... sharpen it or replace it.

On Or About This Date In History 7/12/2012 9:35 AM, Without Any Thought 
D. T. Green Pecked Out The Following:
> Have a small electric drill with a 8mm drill trying to drill through some
> mild steel about 7 mm thick.
>
> The drill is pretty blunt. I'm leaning on it and making little progress.
>
> I know the answer is to travel out and buy another drill, but out of
> interest; that so called 'milk' used on lathes (mixture of oil and water i
> believe) would that help me in this situation?
>
> One aspect is that the drill is so hot, i'm wondering if all the temper
> could be taken out of it, without some coolent?
>
>

Coolant and lubricant are not the answer.  Sharpening the bit will work 
wonders.  If you don't know how, get a new one.


-- 
Just West Of Nowhere
Enjoy Life And Live It To Its Fullest As
It Has An Expiration Date
Support Bacteria: They Are The Only Culture Some People Have

D. T. Green wrote:
> Have a small electric drill with a 8mm drill trying to drill through some 
> mild steel about 7 mm thick.
> 
> The drill is pretty blunt. I'm leaning on it and making little progress.
> 
> I know the answer is to travel out and buy another drill, but out of 
> interest; that so called 'milk' used on lathes (mixture of oil and water i 
> believe) would that help me in this situation?
> 
> One aspect is that the drill is so hot, i'm wondering if all the temper 
> could be taken out of it, without some coolent? 
> 
> 
WD-40, motor oil, real cutting oil. But even using any of those is going 
to be a waste of time if your drill RPM is too high. Use a drill press 
and keep the RPM's around 800 or less. And start with a fresh quality bit.

HTH

-- 
http://www.privacySOS.org | www.extinctioncrisis.org
www.snuhwolf.9f.com|www.savewolves.org
    _____  ____  ____ __ /\_/\ __      _ ______   _____
   / __/ |/ / / / / // // . . \\ \ |\ | / __ \ \  \  __\
  _\ \/    / /_/ / _  / \     / \ \| \| \ \_\ \ \__\  _\
/___/_/|_/\____/_//_/   \_@_/   \__|\__|\____/\____\_\

On 12/07/2012 15:35, D. T. Green wrote:
> Have a small electric drill with a 8mm drill trying to drill through some
> mild steel about 7 mm thick.
>
> The drill is pretty blunt. I'm leaning on it and making little progress.
>
> I know the answer is to travel out and buy another drill, but out of
> interest; that so called 'milk' used on lathes (mixture of oil and water i
> believe) would that help me in this situation?
>
> One aspect is that the drill is so hot, i'm wondering if all the temper
> could be taken out of it, without some coolent?
>
>

I recently had to drill some 8mm diameter holes through 6mm mild steel 
with a HSS bits and a cheap power drill. I was expecting it to be 
difficult, but I found that by starting with a 3mm drill and working up 
in 1mm increments, it was easy.

I guess this approach might lead to the hole wandering a bit, and could 
cause uneven wear on the drill bits.

On Thu, 12 Jul 2012 15:35:06 +0100, D. T. Green wrote:

> Have a small electric drill with a 8mm drill trying to drill through
> some mild steel about 7 mm thick.
> 
> The drill is pretty blunt. I'm leaning on it and making little progress.
> 
> I know the answer is to travel out and buy another drill, but out of
> interest; that so called 'milk' used on lathes (mixture of oil and water
> i believe) would that help me in this situation?
> 
> One aspect is that the drill is so hot, i'm wondering if all the temper
> could be taken out of it, without some coolent?

The steel may be case-hardened. Get yourself a stainless steel bit rather 
than HSS. By 'stainless steel' I don't mean made of that metal, I mean a 
drill bit specially made for stainless steel.



-- 
You do not have to say anything, but it may harm
your defence if you do not mention when questioned
something which you later reply on in court. Anything
you do say may be given in evidence. Do you understand?

Aardvark <aardvark@aardvark.uk.tc> wrote in
news:jtn6r1$pbf$1@dont-email.me: 

> On Thu, 12 Jul 2012 15:35:06 +0100, D. T. Green wrote:
> 
>> Have a small electric drill with a 8mm drill trying to drill through
>> some mild steel about 7 mm thick.
>> 
>> The drill is pretty blunt. I'm leaning on it and making little
>> progress. 
>> 
>> I know the answer is to travel out and buy another drill, but out of
>> interest; that so called 'milk' used on lathes (mixture of oil and
>> water i believe) would that help me in this situation?
>> 
>> One aspect is that the drill is so hot, i'm wondering if all the
>> temper could be taken out of it, without some coolent?
> 
> The steel may be case-hardened. Get yourself a stainless steel bit
> rather than HSS. By 'stainless steel' I don't mean made of that metal,
> I mean a drill bit specially made for stainless steel.
> 
Prolly a carbide tipped drill then.

-- 
http://www.skepticalscience.com/
http://stopbeck.com|www.snuhwolf.9f.com|www.eyeonpalin.org
    _____  ____  ____ __ /\_/\ __      _ ______   _____
   / __/ |/ / / / / // // . . \\ \ |\ | / __ \ \  \  __\
  _\ \/    / /_/ / _  / \     / \ \| \| \ \_\ \ \__\  _\
 /___/_/|_/\____/_//_/   \_@_/   \__|\__|\____/\____\_\

On Jul 12, 3:35 pm, "D. T. Green" <gree...@mail.invalid> wrote:
> Have a small electric drill with a 8mm drill trying to drill through some
> mild steel about 7 mm thick.
>
> The drill is pretty blunt. I'm leaning on it and making little progress.
>
> I know the answer is to travel out and buy another drill, but out of
> interest; that so called 'milk' used on lathes (mixture of oil and water i
> believe) would that help me in this situation?
>
> One aspect is that the drill is so hot, i'm wondering if all the temper
> could be taken out of it, without some coolent?

Blunt drills don't drill.  It is buggered now if you have been pushing
on it regardless. You need to sharpen immediately they go blunt.  It
may be a cheapie only intended for wood. You want a tool/carbon steel
or cobal tipped drill.

The "milk" is soluble oil.  ie an oil that makes an emulsion with
water.

You can use WD40 as a coolant/lubricant.
Drill a small hole in steel & then progressively larger.

Parko wrote:
> On Thu, 12 Jul 2012 15:35:06 +0100, D. T. Green wrote:
>
>> Have a small electric drill with a 8mm drill trying to drill through
>> some mild steel about 7 mm thick.
>>
>> The drill is pretty blunt. I'm leaning on it and making little progress.
>>
>> I know the answer is to travel out and buy another drill, but out of
>> interest; that so called 'milk' used on lathes (mixture of oil and water
>> i believe) would that help me in this situation?
>>
>> One aspect is that the drill is so hot, i'm wondering if all the temper
>> could be taken out of it, without some coolent?
>
> If the drill bit is 'blue' throw it out. A sharp tool is a safe tool. A
> new drill bit is cheap enough and will save you an injury. A drill press
> and decent vise would be best for the job. Investing in a drill sharpener
> will save time and money in the long run.
> http://www.carbatec.com.au/drill-doctor-drill-bit-sharpener_c19755
> There are cheaper alternatives around.
>
>

Most of the problems with drilling are caused by speed and pressure, 
pressure being the main problem with non tradespersons, use as much 
pressure as you can with out breaking the drill, this comes with experience.

"D. T. Green"  wrote in message news:jtmnb0$ovi$1@dont-email.me...

Have a small electric drill with a 8mm drill trying to drill through some
mild steel about 7 mm thick.

The drill is pretty blunt. I'm leaning on it and making little progress.

I know the answer is to travel out and buy another drill, but out of
interest; that so called 'milk' used on lathes (mixture of oil and water i
believe) would that help me in this situation?

One aspect is that the drill is so hot, i'm wondering if all the temper
could be taken out of it, without some coolent?

vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv

All the other replies have pretty much covered it, but I'd emphasise that if 
you've "blued" the cutting end trying to grind your way through the metal, 
you've ruined the temper of the steel the drills made of - otherwise I'd 
suggest tou get someone to teach you the art of sharpening drill bits, too 
late for that now - throw it away & buy a new one.

If you were drilling sheet steel I'd issue a stern warning about the danger 
of the drill catching as it breaks through and spinning the workpiece so it 
scythes through your hands - not such a risk with 7mm, but I'd heed the 
advice others have given to clamp the work piece on a pillar drill stand.

As for lubricants - I'm a bit stingy myself and tend to use what's to hand 
rather than buy expensive special products.
I generally get good results with molybdenum disulphide wheel bearing 
grease, Slick50 or Finnish-line teflon bicycle grease. 

On Fri, 13 Jul 2012 14:44:09 +0100, Ian Field wrote:

> If you were drilling sheet steel I'd issue a stern warning about the
> danger of the drill catching as it breaks through and spinning the
> workpiece so it scythes through your hands - not such a risk with 7mm,
> but I'd heed the advice others have given to clamp the work piece on a
> pillar drill stand.

Heh. That reminds me of a job I did some twenty years or so ago in BHS in 
Liverpool.

We were fixing heavy galv angle (3 X 3) to a concrete soffit using Hilti 
fixings, then fixing hangers of the same material to this angle, using 
9mm bolts.

Having fixed a couple of lengths of the angle to the soffit, we'd then 
clamp some hangers to the angle at 600mm centres then drill a 9mm hole 
through the two thicknesses of metal for the bolts. As I was having to 
hold the drill over my head, a big drill weighing 3kg would have been a 
bit too tiring on the arm (believe me, we checked this :-)) so my mate 
brought in a powerful little drill he had at home made by a company I'd 
never heard of before or since called De Souter.

It was high Summer and, as the store was still open for business, our 
work area was completely encapsulated in Visqueen- the thick polythene 
sheeting you see used on sites for all kinds of purposes. It was like a 
Turkish bath in there, and we were all sweating heavily the whole time we 
were in there.

The De Souter was a marvellous drill, plenty of power, adjustable speed 
and would fit nicely into the palm of my hand. Except the body was made 
completely of smooth, shiny steel, or perhaps aluminium. Combined with 
sweaty hands, it was, in retrospect, an accident waiting to happen.

While I was drilling one of these holes, increasing my grip just before 
the bit emerged from the other side as usual (there's always, as you 
said, a catch as the bit emerges), suddenly the bit caught. The torque of 
the drill twisted it out of my sweaty hand and the bit snapped. Not a 
straight snap, but a helical one, leaving part of the bit in the metal 
and the rest of it in a pointy corkscrew shape in the drill, which fell, 
bit first.

This corkscrew embedded itself in my breastbone, through skin and muscle. 
The whole drill was actually stuck at an oblique downward angle into my 
chest. My mates beside me had watched all this happening and couldn't 
move for laughing at the sight of me with a hand drill sticking out of my 
chest. I let them laugh for a minute or so and then pulled it out.

It could have been much, much worse, but the end result was a tiny, 
almost imperceptible hole in the middle of my chest and one drop of 
blood. I think the fact that the drill bit- what was left of it- was so 
hot it cauterised the wound. We were all pretty amazed at the outcome.

A slight throb in my breastbone for a few days, and that was it.

-- 
You do not have to say anything, but it may harm
your defence if you do not mention when questioned
something which you later reply on in court. Anything
you do say may be given in evidence. Do you understand?

On Thu, 12 Jul 2012 18:39:15 +0100, RustyCrampon
<rusty@invalid.invalid> wrote:

>I recently had to drill some 8mm diameter holes through 6mm mild steel 
>with a HSS bits and a cheap power drill. I was expecting it to be 
>difficult, but I found that by starting with a 3mm drill and working up 
>in 1mm increments, it was easy.
>
>I guess this approach might lead to the hole wandering a bit, and could 
>cause uneven wear on the drill bits.

It's the way I've done it for decades - I always use a pilot drill of
2mm or greater.

In article <4fff0b95$0$14738$a8266bb1@newsreader.readnews.com>, 
RustyCrampon <rusty@invalid.invalid> writes
>On 12/07/2012 15:35, D. T. Green wrote:
>> Have a small electric drill with a 8mm drill trying to drill through some
>> mild steel about 7 mm thick.
>>
>> The drill is pretty blunt. I'm leaning on it and making little progress.
>>
>> I know the answer is to travel out and buy another drill, but out of
>> interest; that so called 'milk' used on lathes (mixture of oil and water i
>> believe) would that help me in this situation?
>>
>> One aspect is that the drill is so hot, i'm wondering if all the temper
>> could be taken out of it, without some coolent?
>>
>>
>
>I recently had to drill some 8mm diameter holes through 6mm mild steel
>with a HSS bits and a cheap power drill. I was expecting it to be
>difficult, but I found that by starting with a 3mm drill and working up
>in 1mm increments, it was easy.
>
Not really best practice as you're only taking 0.5mm off each side of 
the hole each time and not using the main cutting faces of the drill 
bit. For 8mm I'd go 3mm pilot then straight to 8mm.

For a bigger size I'd happily pilot at 6 then jump up from there.
-- 
fred
it's a ba-na-na . . . .