Drilling 4mm Steel

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

Reply to
N. Thornton
Loading thread data ...

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

Reply to
Dave Gibson

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

Reply to
Kalico

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.

Reply to
IMM

If it's ordinary mild steel, you only need decently sharp HSS drills - starting with a small one, and working up in diameter to the final size. It helps enormously if you can mount your drill in a pillar drill stand, rather than hand-holding it - since that enables you to apply a lot of pressure with less risk of breaking the drill bit. It also helps if your electric drill has a 2-speed gearbox - in which case you should use the lower speed setting.

If you don't know whether it's mild steel, test it with a sharp hacksaw or the edge of a triangular section file. If it cuts easily, it will drill easily with the right kit. If you can't cut or file it, it's probably something more exotic than mild steel - and you probably won't be able to drill it either.

Reply to
Set Square

(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.)

Reply to
Michael Mcneil

"Kalico" wrote in news:0yKEb.3003$ snipped-for-privacy@wards.force.net:

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

Reply to
mike ring

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.

Reply to
IMM

You need a HSS (high speed steel) bit - which will probably be dark blue/black in colour. It's possible the general purpose one you tried wasn't made for steel. The sheds sell them separately or in sets.

You need to apply a fair bit of pressure - not like drilling wood. Use a slow speed, about 1000 rpm, and start with about 5 mm. Use some light oil to help the cutting process and keep things cool - if the drill overheats it'll go blunt and need sharpening - not easy if you're not used to doing this. If you've got a drill stand it makes it much easier to apply vertical pressure with less risk of breaking the drill. You really need somewhere approaching your entire body weight, pressure wise, to drill steel easily.

I'm amazed you got anywhere - the cutting angles of a masonry drill are all wrong for steel.

Reply to
Dave Plowman

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

Reply to
Kalico

Very slow drill speed and lubrication - soapy water from memory, and good quality standard drill bit.

Reply to
The Natural Philosopher

God, what little englander drivel you do spew.

Reply to
The Natural Philosopher

What? HSS would help the war effort?

Reply to
IMM

The obvious comment is that the drill bit was broken. I've an 8mm & 10mm drill bit that takes about 10minutes to go thro T304. Well it was T304 when it started, it usually ends up several colours later.

More seriously, there are a lot of "one-use" drill bits out there and that includes some from B&Q and even some from proper jobber shops.

If the person was drilling stainless, anything less than a fresh quality drill bit can make it an excitingly long experience if 4mm or more. The fact it is causing discolouration means it is heating, not cutting and pretty obviously the bit is broken - probably by age/heat/dropping.

-- Dorothy Bradbury

formatting link
for fans, books & other items

Reply to
dorothy.bradbury

The best drill types for metal are center drills,cut through like butter,but not available in the sheds go to a tool shop or engineering supplies.You will be amazed at the speed.

Reply to
Alex

sure, search uk.d-i-y for thornton, toilet, door. But yes, this one was serious.

hehe.

lol, never had any problems doing it before, but then it was always

1.6mm or so.

Well it has a very different angle to the usual masonry, so maybe on reflection its not a masonry bit, its TCT anyway, with the cutting edge at 90 degrees to the cuttee.

Here youre surely kidding. I've made many a hole that took longer than that.

:)

lol! too funny.

I didnt miss that, no. I'm not the kind that gives up easily.

Thanks for the laugh :) Yes OK, I didnt get it quite right eh.

Regards, NT

Reply to
N. Thornton

Thanks Dave, this explains it all. I'll dig out another smaller bit and try again, at lower speed, with oil, and a lot more pressure.

Thanks to you and the other helpful contributors, NT

Reply to
N. Thornton

Or drilling anything other than ABS or pine...

IMHO the order of importance is:

1) Correct drill material - HSS in this case. 2) Sharp with correct angles. (New drills aren't really sharp BTW...) 3) Correct speed, just a few hundred RPM. 4) Lubrication/cooling, probably only really required if trying to drill a big hole in one go. You need a pilot hole around the size of the web of the next drill (ish you don't want to try and take "to much" in one go. 5) Rigid mounting of drill and work, this really does make a great difference to the accuracy of holes. Small pillar drills are available for
Reply to
Dave Liquorice

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

Reply to
Steve

HomeOwnersHub website 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.