Best drill bits for drilling into steel beams

[Deansplit]

Hi
I fit plantation shutters and the amount of hours I've lost through getting dead arms and breaking drill bits drilling upwards is just not funny anymore. I've tried the usual brands like Bosch, even hi-speed bits and they seem to only last for 2 or 3 holes or so. Is this usual? If so, I'll make sure I factor in the price of bits onto jobs which have steel beams or are metal bits designed to go blunt after such short use? Once the initial small hole is made, opening it up to the desired size seems to be a doddle, presumably because it's the tip of the bit which gets blunted and the sides still remain sharp so bore it out easier.

Any help in technique and which type to buy would be greatly appreciated.

Thanks

 

[Tigercubrider]

Try cobalt tipped drills.
Going too fast can knacker drills


I always thought that there should be an affordable device like an upside down drill press that made drilling ceilings easier

 

[EddieM]

Try cobalt tipped drills.
Going too fast can knacker drills


I always thought that there should be an affordable device like an upside down drill press that made drilling ceilings easier

Magnetic drill ? TPP hard drills plus cutting paste.

 

[Deansplit]

Thanks guys - yeah TTP (not TPP by looks of it?) look good!

 

[Nozzle]

Get the speed right for the diameter of drill,

Nozzle

 

[EddieM]

Thanks guys - yeah TTP (not TPP by looks of it?) look good!

Yeah sorry TTP slow speed no hammer obs

 

[bobsuerita]

hole saws are good i always use 12mm one for bolt holes in steels that often get missed or put in wrong place but youre best bet is as stated above

 

[SammyInnit]

2 or 3 holes or so. Is this usual?

Absolutely not. I can get months out of a HSS drill before it's painfully blunt. And even then it's avoided by using cutting oil, low speed depending on diameter and letting the drill work.

I don't want to tell you how to suck eggs but something isn't right in what you're doing.

Edit: Always pilot your holes first. When drilling I beams or heavy gauge steel I'll use a small pilot but not so small that any force will snap it, personally 4.5mm. If the desired final hole is say 10mm I'll use an 8mm after the pilot and then the 10mm. Sometimes another bit in the scale just to help when it's heavy material.

Cobalt bits are good, last well and cut well but they're expensive so I tend to use these for smaller pilot bits. Pilot bits can be run faster but don't put too much force on as they'll overheat and blunt, as I said let the drill do the work and keep backing out to clear the flutes.

For bigger diameters the best value for money I've found is in HSS Heller brand bits. Run them slower. If you can get cutting oil, every few minutes just dip the drill tip in a jar full to keep it cool and lubed up.

 

[SammyInnit]

Try cobalt tipped drills.
Going too fast can knacker drills


I always thought that there should be an affordable device like an upside down drill press that made drilling ceilings easier

Depends what you consider affordable but mag drills can be had for a few hundred quid these days. Only going to work if you have a clear metal surface though.

 

[Tigercubrider]

I thought more along the lines of those slightly toy town drill stands that people used to turn their black and decker into a drill press but designed to go upwards, and a telescopic pole to jam it against the floor

I once used a stamp ladder with a pole across it to encourage a drill upwards as I pushed down

 

[SammyInnit]

I thought more along the lines of those slightly toy town drill stands that people used to turn their black and decker into a drill press but designed to go upwards, and a telescopic pole to jam it against the floor

I once used a stamp ladder with a pole across it to encourage a drill upwards as I pushed down

One of these under the drill would do the job.

 

[aptsys]

When drilling you want spiral shavings. If you get little chips of metal you're not applying enough pressure and the drill bit will go blunt fast. Cutting oil is almost always pointless unless you're in a machine shop.

 

[SammyInnit]

When drilling you want spiral shavings. If you get little chips of metal you're not applying enough pressure and the drill bit will go blunt fast. Cutting oil is almost always pointless unless you're in a machine shop.

The principal is the same in a machine shop as anywhere else. What's good for the goose is good for the gander.

 

[EddieM]

Depends what you consider affordable but mag drills can be had for a few hundred quid these days. Only going to work if you have a clear metal surface though.

Not quite a "couple of hundred" quid that one..... but I want it! (Not that I have any need for it)

 

[SammyInnit]

Not quite a "couple of hundred" quid that one..... but I want it! (Not that I have any need for it)

Oh no, not that one, and the stock photographer forgot to insert the battery too lol. Does look good for people who it is a constantly used tool.