What's the secret to drilling through 1/4" angle iron?

[tallyho8]

I have to drill 40 quarter inch holes through 1/4" angle iron with a hand drill. I've tried most of the different drill bits that Home Depot sells and they usually get too dull to drill after 2 holes.

Is there a better drill bit I can buy or am I doing something wrong in the way I am drilling?

 

[deezler]

I'm no expert on this and would also like to learn. However, I would suggest the following:
1) use oil/lubrication. Tap magic or the like, at least some squirts of WD40.
2) go slow, you aren't in a race to rip through it. If you're making lots of smoke, you're doing it wrong.
3) use a drill press so that you have good control of the pressure and alignment
4) Get a drill doctor and don't be afraid to tune up your own drill bits, repeatedly if needed.

 

[MH8675309]

What deezler said +1 specially the drill doctor part.

 

[AaronS]

+1 on what deezler said, plus drill a pilot hold of about 1/8", then step up to the 1/4".

 

[PHPaul]

Most likely your drill is turning too fast. Move up to a half-inch drill (motor, not bit) they run a lot slower and won't burn the bit.

Lean on it enough to keep a curl of metal coming off the bit. Too little pressure is as bad as too much.

Lube is good.

I don't do pilot holes until I get MUCH bigger than 1/4". All that does is put all the stress on the outside edges of the bit where it's the weakest.

 

[Mike68]

To expand on the "go slow" comment. This means less pressure. Don't bear down on the drill bit too hard. Let the drill bit do the work. A good Colbalt drill bit should have no problem drilling 40 holes. The purpose of the lubrication is to remove heat. Use it liberally. Heat is your enemy. If the steel is turning blue then you are generating too much heat. That is either a dull drill bit and/or too much pressure.

 

[bigdeano]

If the drill bits are any good they should do all 40 holes without getting dull. Maybe they're turning too fast. A 1/4 drill shouldn't turn more than about 1500 rpm in mild steel.

 

[Ed of all trades]

Is it 1/4 angle IRON? or is it scrap and a hardened steel? Ed

 

[Fawken]

A small drill press (around $100) allows you to use carbide bits which you can get locally or order custom twist and cut angle. For 1/4" steel, a 1/4" carbide masonry bit will punch right through. That tip was passed on to me by a machine shop when I needed to drill precise holes in hardened stainless steel. I didn't believe a masonry bit could cut steel, but the carbide bits in a drill press and at the right speed work magic.

 

[Colcreate]

One of the guys from a workshop I managed once complained about the quality of drill bits I gave him, until I showed him the forward position on the forward/reverse switch.....
Quality HSS drill bits should be fine on steel angle, as others have said correct speed, pressure and cutting fluid/oil all count towards success.
If it's really tough steel then look for 5% Cobalt HSS bits.
Masonry drill bits would require sharpening to the correct cutting angle before they will cut steel, I've used them occasional for difficult jobs on welded stainless that has toughened during fabrication.