Drilling through steel/metal/colorbond

[lozandsam]

Had a go at putting together a colorbond fence over the weekend, while we got the job done, each hole I had to drill took a good few minutes each. I've watched just about every tutorial for drilling through steel and it just seems to go straight through alot easier than I was doing it, what am I doing wrong?? I'm just using a standard cordless drill (which from what I can gather is all I need) and a heavy duty cobalt bit. I'm pre drilling each hole, then using self drilling tek screws to fasten. Am I not using the correct tools?

It turned a relatively easy job into a full day mission because the drilling just took so long...

[Noyade]

"I'll take a photo this afternoon of my drill bit to see if you can identify any issues."

That would be interesting to see. Based on your experience, there has to be something wrong with the drill bit.

Did you try another 4mm drill bit?

[Noyade]

As Eric mentioned - a punch might be useful prior to drilling. But the 5 minute story is clearly excessive....

If there is wood behind the corrugated iron I tend to use this. The wine is just a bonus.

[r23on]

For all sheet metal twist drills are a waist of space they catch and rip the sheet a very smart person designed step drills and bunnings has a range of cheap to not so cheap step drills They can be used for a wide range of tasks including drilling plastic. 

https://www.bunnings.com.au/craftright-3-piece-step-drill-set_p0027584 

https://www.youtube.com/watch?v=KBrjkqPpVvo 

[Noyade]

"For all sheet metal twist drills are a waist of space"

Gonna have to disagree mate.

Experiment...

Cheap drill bits.

Cheap cordless (10.8V) Aldi drill - set to high speed.

1.5mm sheet metal.

Two 4mm holes drilled in 24 seconds.

Experience - priceless!

There has to something quite wrong with the opening poster's drill bit, as surmised by Mitchell on the previous page.

[r23on]

Thats the beauty of this forum everyone has the opportunity to provide information and experience, a step drill 4mm set in cheap drill at heigh speed same thing no possibility of catching