Drilling 4mm Steel

Page 1 of 2  
Hi
I need to drill some 4mm sheet steel, but am having no luck on tries 1 and 2.
1 was with a general purpose drill bit, which became blunt in about 2 minutes, and the end bue/black from the heat.
2 was with a tunsten carbide masonry bit, which survived ok but was unusably slow. It produced fine powder very very slowly. 20 minutes of drilling got most of the way through one hole.
What kind of bit should I be using? Or where else am I going wrong? The drill is a decent mains one. I'm not really set up for driling steel.
Thanks, NT
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Use a decent quality HSS bit. You don't mention the drill size, but your drill speed should be around 700 rpm for a 1/2" bit, up to 1500 rpm for a 1/4" hole in mild steel. For a hole of 4mm depth I would also use some coolant, ideally soap oil but for a one off any thin machine oil like 3 in 1 will do. If you are set up correctly you should get through that hole in less than 20 seconds!
Dave
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Those speed recommendations appear to exactly agree with my copy of the Dormer Twist Drill and Reamer Handbook recommendations for the lowest grades of mild steel. But, those are speeds for optimised conditions in high speed production environments i.e. rigid machinery setups, drills in perfect condition, the correct coolant/lubricant. They also balance the cost of replacing/resharpening the drills on a regular basis with the need to get fast throughput which means running faster than the drill bit would ideally like to survive forever. For DIY use, especially with hand tools you can forget them. In fact halving them isn't too much. Even on my milling machine if I want my drills to last for the sake of taking a few seconds more I rarely run at more than 550rpm with drills of the 8mm to 10mm range. I hardly ever have to resharpen a drill because I don't burn them out.
For a hole of 4mm depth I would also use some

To the OP. The average hand power drill runs far too fast for drilling in steel, even mild steel. If you have a variable speed control then wind it down as far as it will go but it will still probably be too fast. A few hundred rpm is ideal and only special high torque/low speed drills do that. Drill bits burn out in seconds when they run too fast.
Buy decent quality HSS drill bits. Go to your local Engineers Merchants (yellow pages) and see what they have on special offer. Kamasa, Dormer, anything German is what the pros use in engineering shops. Forget Halfrauds and other mickey mouse car bits suppliers. You can often get a set of quality 1mm to 10mm drills in 0.5mm increments for under 20.
Use a centre punch to locate the drill bit and start with a small drill, say 5mm, which will be better suited to the over fast power drill. Then work up in 2mm increments to enlarge the hole. Use a squirt of any sort of oil to cool and lubricate the cut. Engine oil is ok at a pinch. Having said that I run dry on the mill because oil makes the swarf stick to everything but then I'm running at very slow speeds and on a rigid machine. I'll drill through every 1mm in a couple of seconds without ever burning a drill out.
Get a good quality drill bit at the right speed and you'll wonder why you ever had a problem because it'll cut mild steel like butter.
Dave Baker - Puma Race Engines (www.pumaracing.co.uk) I'm not at all sure why women like men. We're argumentative, childish, unsociable and extremely unappealing naked. I'm quite grateful they do though.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I hesitated to say this against the advice of those much more skilled than me, but on my own cheap (40 quid) B&Q pillar drill I leave it on the low speed for everything. I've not developed the art of sharpening small drills, and although they're cheap enough that doesn't help if you need one *now*.
Luckily, with most mains drills, enough pressure will slow them down considerably, and a pause to let things cool down will help too.
One good source of small drills is autojumbles - you'll get a pack of ten designed for production use for the cost of one from a shed.
--
*There are two sides to every divorce: Yours and shit head's*

Dave Plowman snipped-for-privacy@argonet.co.uk London SW 12
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Although answering this, I am not entirely sure this is not a wind-up. Can you convince us it is not?
Frankly, if you do convince us it is not, then many on this group will be a little worried that you are practicing DIY on a property that someone may (God help them) buy from you. I honestly don't mean to ridicule you here, but what you say does encourage it. Also, before any flaims come in, I am not intending to be rude. But I am sure I am not the only one smiling wryly at the mo.
I agree that you are most certainly not set up for drilling steel.
20 minutes drilling to get most of the way through a single hole? Masonry bit to drill 4mm steel? Good grief!
I can see why you might have (mistakenly) tried the 'general purpose' bit, but did you not think 2 minutes a little long to keep going for? I suppose it is not as long as 20 minutes.
Two things you might want to check before you drill anything, ever again, are :- (1) which direction the drill is rotating in (2) the time when you start - if you notice the hour hand moving, stop drilling
OK, fun over. Assuming you really did miss the fact that a masonary drill might be for masonary and not 4mm steel, what you need is a small diameter drill bit suitable for steel. No more than 2mm, drill a hole, then drill another with a 4mm bit suitable for steel. Those marked HSS - High Speed Steel, should do the job.
For future work, remember the old saying "Give us the tools and we'll do the job" or something similar I remember my old Dad muttering when I was a lad etc.
Best regards Rob
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Winston Churchill said that when asking for US equipment to fight the Germans. They didn't give us the tools, they sold us them with interest bankrupting the country as the British were fighting their war, holding back the Germans until the US rearmed. We fought their war, to give a breath space, with their tools and they charged us and we ended up poverty stricken; ask anyone being brought up in the 1940/50s of the austerity in the UK. Something wrong there me thinks.
Now if we had better high speed drill we would not have needed the Yanks tools.
--
--

Checked by AVG anti-virus system (http://www.grisoft.com ).
Version: 6.0.552 / Virus Database: 344 - Release Date: 15/12/2003
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I think you will find that the second world war was a continuation of WWI. If you think drilling mild steel with a maonry bit is a little ott wait until you find out what that traitor Churchill was using for a labourer to build his wall.
(Despite the fact that the country was being run by Cons in the 30's, it took a real hero to give Poland to Joseph Stalin.)
--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

No it wasn't. Totally different and 20 years between.

He built his own wall in his garden. A wall from nowhere to nowhere keeping nothing in or out. A wall. A DIY wall. If he was alive today he would have asked Qs on here about why his wall was wobbly.

Stalin took it and we had no option but to say yes.
--
--

Checked by AVG anti-virus system (http://www.grisoft.com ).
Version: 6.0.552 / Virus Database: 344 - Release Date: 15/12/2003
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
IMM wrote:

God, what little englander drivel you do spew.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

What? HSS would help the war effort?

--
--

Checked by AVG anti-virus system (http://www.grisoft.com ).
Version: 6.0.552 / Virus Database: 344 - Release Date: 16/12/2003
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
The Natural Philosopher wrote:

Actually, he speaks an awful lot of truth here. It is a fact that Roosevelt made the UK liquidate ALL its US assets to pay for the materials they supplied.
I think it took until 1990 until holdings by UK companies in the USA regained their original level.
Steve
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

N. Thornton has posted many times in this group, and has showed no trollish tendencies

I'm smiling wryly, too, because I've BTDT, and it may be the toffee drills I innocently bought, or the kryptonite I was trying to drill, or lack of knowledge, but I certainly recognise the situation. I've always booked this as a group where people come who need (and usually get) advice not ridicule, and I hope such will not be put off by folks like you
mike r
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
[snip]

Hey Mike - "folks like you" ? What is that? Whatever you are hinting at I, too, certainly hope that people are not put off by it.
Sorry to have tried to introduce a little humour here. Come on though - if the thought of someone drilling away at a piece of steel for 20 minutes doesn't make you chuckle, then maybe you are taking the wonderful world of DIY a little too seriously. And with DIY, that is probably the biggest mistake anyone could ever make, if only due to Murphy's Law....
I tried to make a point of saying I was being good humoured about the winding-up. I guess here lies another example of the drawbacks of text communication.
Best regards to all, including the OP. Rob
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

it's this group; usenet is full of very abusive and sneery types, and this group is usually pretty gentle on the uninformed; I am prolly overanxious to keep it that way.
mike r
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I am keen to keep it that way too. One need only check my past posts to see how gentle I am on beginners. Hell, I even work as a teacher, so sneeriing at the uneducated is not something that would come easily to me.
Merry Christmas Mike Rob
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Not like the teachers I remember, then?
--
*I wish the buck stopped here. I could use a few.

Dave Plowman snipped-for-privacy@argonet.co.uk London SW 12
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Course, we did end up educermated and numeramate
mike r
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

mike r
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Kalico wrote:

Who's him?
Er! What's that about unedcurmutated and innumerably innumerate?
See W.W.II Grandmas Buggins, "Ingrediments" and "Reconstituated" etc.!
Also; my late father, a teacher in the UK for about 40 years, said that a common 'Teachers Common Room' joke was about "Casting sham pearls of wisdom before real swine"!. Oh gosh; that included all of us pupils! :-) (Escaped from the school system in 1952). Terry.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.