What kind of drill bit do I need to drill 1/2 inch holes in 1/4 inch steel? Carbide or ?

Question

What kind of drill bit do I need to drill 1/2 inch holes in 1/4 inch steel? Carbide or ?

Answer 1

If this is plain old carbon steel you just need to first drill a small pilot hole-like 1/8" work up to 1/4" and then 1/2".Use some oil-it doesn't matter what kind,the trick here is to keep the drill bit cool and spin it slow enough so that it doesn't heat up.You don't need a fancy drill-just go slow and use enough pressure to let it cut.Try it-you'll be a pro by the 3rd hole!

Answer 2

Nothing Fancy required. Just ordinary hss bit. the answers that say pilot it first . with an oil to cool etc and then no worries at all. Carbide is for masonry by the way.

Good luck

Answer 3

I would go with a cobalt, it cost a bit more, but with it being 1/4 " you will need some thing that can stand up to the heat, also use a few drops of oil, and low speed

Answer 4

pilot hole and cutting oil.

Answer 5

Its best to start out with smaller bits first ae; pilot holes 1/4" then 3/8" & then 1/2"  drill slowly & add a few drops of oil like the others said.  Use regular carbide bits & this process will work fine.

Answer 6

When looking at drill bits I try to get titanium as the least alloy and / or a cobalt or something harder the harder the alloy the easier it will break.  I broke 1 bit just by dropping it. A hardned alloy is ok but many will not hold an edge. If you have many holes I also suggest a bit sharpner. A good bit will cost over $15.00 any bit less than this is made to sell and not to reuse time and again at least thats what I've found.

Also use a low grade oil to keep the bit edge cuting cool and sharp. Tie the plate down so it wont hang up and spin under your drill. Motor oil will work fine, just a few drops and if the smoke stops drop another couple of drops. The smoke is your sign that the oil is doing its job and if it stops smoking its evaporated.

And pay close attention to the drill as it cuts through the steel, just has it is getting through the final thickness slow your speed or on-ff-on the drill to keep from breaking the bit. Also use a center punch to mark your hole center and to give you a place to start and use the on off on or a slower speed to get your cut started.

You may already know all this but I had to learn it, so this is from my mistakes to help you not to chide you.

Hope this helps and good luck drilling.

Answer 7

Hello Jesse,

You'll need a metal bit, easily found at a hardware store or home center.  You'll need a hefty drill (I know my 14 volt would take three charges for this), and you can ease the work of the bit by applying oil to the drilling spot.  Allow the bit to eat through it slowly.  Remember pressure and speed will only dull the bit.