[worldo]

trying to drill through 5mm flat bar and dulled my drill bit.

I dont have a fancy bench drill. Is there a certain brand/sort of drill bit i should be buying i dont want to spend to much as i probly wont use it again if ever

Cheers
Ricky

[royce]

Sutton, slow the drill down a bit and push harder, will rip right through

[squibby]

I used a $18 Ten pack of bits to drill holes up to 10mm through 5mm steel at the weekend with a cheap hand held drill. Was easy. I predict the bits will drill about 5-7 holes before they are blunt at the rate I was getting through them. You don't have to spend a lot of money.

[mnemonix]

Sutton drill bits all the way. how big a hole are you drilling?
I'm drilling loads of 8-10mm holes in 10mm flat bar lately.
Just using a scummy old hand drill and sutton high speed drill bits.
Start with a 3mm pilot hole and step up a couple of times. 3-5-8-10mm.
Only takes like 60 seconds, and the drillbits are still razor sharp after about 30 holes drilled.

[tanshi]

Good quality drill bit is gonna last alot more than 5 holes

[worldo]

10mm holes i had drill on flat stick and was pressing down. will slow it down and source some sutton drill bits

thanks guys

[bohuler]

A bit of cutting oil will help too. The last thing you want to do is go flat out when drilling. As soon as the end of the drillbit gets hot, it looses its edge and bingo, blunt drill bit, more friction, more heat, ect ect.
If you don't have cutting oil, veggy oil will do or even water at a pinch, anything to lubricate and help the drill bit cut.
A 3mm pilot hole is all you should need for a 10mm hole.

[worldo]

i got vegetable oil will give it a shot on wednesday. thanks for the advice guys.

[Teracis]

worldo wrote:

i got vegetable oil will give it a shot on wednesday. thanks for the advice guys.

Even engine oil will do, you could even use water to keep it cool if you were desperate (or drilling ally, water is boss when drilling/cutting ally)

Just don't overheat the tip and you will be fine!

[alexvitara]

you can also do it with squirts of the drill.
1 second bursts with lots of pressure.
if you do burn out your drill bit dont keep going, stop and sharpen it or get a new bit.

[worldo]

dont know how to sharpen a drill bit so thats not an option

[3cyl]

worldo wrote:

dont know how to sharpen a drill bit so thats not an option

Just grind the bit on the same angles as it already is. Keep quenching the bit in water to keep it cool and sharpen it before it goes blue.

[shakes]

Stepping it up in small incriments as above can be just as bad for the drill bit.

Pilot hole with a 30bit.

Then 10mm straight through afterwards. Drill slowly with a firm hand and you wont have a drama. Even with a cheap drill bit. At work I can literally do 30-40holes a day like this if not more and a bit lasts a couple of weeks. Spinning it up fast heats it up, and will dull the bit as quick as you can blink and you will be there for days.

[bohuler]

http://www.ebay.com.au/itm/Drill-doctor ... 4aa3b69d69

I have one of these puppies cause I'm lazy Its not very difficult to sharpen a drill bit on a grinder but these things make it a breeze.

[ajsr]

slow drill speed and cutting oil is the ticket and bits will last forever.

suttons and p&n have always been good to me.


and a drill press always helps

[worldo]

dont drill enough holes to need a press but would be very hand right now.

ill buy a new drill bit
slow the drill speed down
and use some oil

should be all sweet.

[thesupervisor]

http://www.dewalt.com.au/accessories/pr ... archy/128/
i use these im a mobile site welder im getting 50+ 1/2 holes out of each bit cost about $14 each the trick is keep a firm pressure when drilling or you lose the temper and then its ruined and control the speed lube is a must if doing more than 4 holes one after the other

[rick1970]

shakes wrote:

Stepping it up in small incriments as above can be just as bad for the drill bit.

Pilot hole with a 30bit.

Then 10mm straight through afterwards. Drill slowly with a firm hand and you wont have a drama. Even with a cheap drill bit. At work I can literally do 30-40holes a day like this if not more and a bit lasts a couple of weeks. Spinning it up fast heats it up, and will dull the bit as quick as you can blink and you will be there for days.

+1

While a pilot is not necessary for holes under 1/2" in a drill press, a small pilot is a help when using a hand drill. Even drilling 1-1/2" holes at work the other day was only a 2 step increase, 1/2" pilot then straight to 1-1/2"". Auto feed radial drill makes it a bit easier tho .

Its keeping a constant firm pressure on the bit thats the trick with a hand drill. Let the pressure off and the drill rubs instead of cuts, cooks, and thats the end of it. Keep the drill speed correct (can be hard with a hand drill), too slow on a small drill is as bad as too fast on a big drill .

Lanotec (lanolin) is a pretty handy cutting fluid when using a hand drill.

[Bucketload]

[Polar_Bear]

<flame suit on>

sutton and p&n used to be good, but unless you get their premium range, which is still made in oz, arent all that great.

<flame suit off>

all the cool kids are using dormer or bordo.....at half the price