Drill bit advice needed...

[Cheeseheadbob]

Well, after burning up, breaking and stripping about 6 drill bits supposedly rated to drill through steel, I am wits end. I am trying to drill a countersunk 1/8" hole through 1/4" angle iron.

I am thinking that the "Joe Home Owner" stuff they sell at the DIY stores is not where I am going to find what I need.

Thanks in advance for the superb information I will receive! :beer:

[MyBlackBeasts]

Well, after burning up, breaking and stripping about 6 drill bits supposedly rated to drill through steel, I am wits end. I am trying to drill a countersunk 1/8" hole through 1/4" angle iron.

I am thinking that the "Joe Home Owner" stuff they sell at the DIY stores is not where I am going to find what I need.

Thanks in advance for the superb information I will receive! :beer:

Cobalt or Titanium are best for drilling steel but really require skilled operator as they are very brittle and will break if not used correctly.

I saw these https://baddogtools.com/styled-6/styled-8/index.html on Cool Tools and was going to try them out. They demonstrated drilling thru many materials w/o breaking and remainied sharp.

At a minimum, use high speed steel to drill your angle iron. Regular will burn up and you will use many to finish the hole.

If the piece of angle is Stainless, that is a radically different story!

[Green96]

Did you center punch the hole before you started? +1 for cobalt or titanium, but you need to center punch the hole first to keep it from walking. I would also recommend that you use a slightly larger drill to start it. Do not drill all the way thru, just go deep enough that you have a drill spot started that is about the diameter of your final drill. I would try a 3/16th or 1/4 for putting in the drill spot.

If it is really tough, you might need some lube too. Just use a drop of motor out, or spray some WD40 on it.

Oh, and don't push too hard. Let the drill do most of the work.

Good luck.

[lifespeed]

I prefer cobalt steel bits. That "titanium" stuff is just marketing hype - some sort of coating. There is no such thing as a titanium drill bit.

Use a light oil lubricant and reapply. Don't let the piece get to hot or it will harden and be impossible to drill.

[Mr. Man]

Any high speed drill bit should work providing it's sharp. Drilling thru steel requires slower drill speed for good progress and like someone said some lubricant can't hurt. Motor oil will work but it's going to smoke the place up. Can't remember what we used to use in the shop.

Are you using a drill press? Trying to drill though thicker steel with a hand drill and tiny drill bits will usually get you lots of broken bits as they snap easy if they are torqued latitudinally.

Slow and steady Bob, works every time. (TWSS)


PS Please wear eye safety glasses :cool: as a chip of steel to the eye is not pleasant and potentially disastrous.:beer:

[Green96]

Yes, titanium is only a coating but it works. I specified tooling and machining processes as a manufacturing engineer for 6 years. The titanium coating helps keep you from getting the base tool too hot.

[cj7chris]

Unibits work better at drilling steel versus conventional bits for me.......

[RubberCtyRauder]

Small drills can quickly round off the point and thus just rubbing and work hardening the piece. A good sharp drill should drill thru angle iron easily. Definitely use cutting oil, even wd40 and center drill it so the drill has a place to start since it is small. Many brands are decent, but make sure it is for metal..Irwin, Cleveland twist drill, Hertel, Vermont american, Precision twist drill, Milwaukee and many others. Titanium drills are actually TIN coated and usually gold colored which helps with tougher materials, tool steels and gummy materials like brass etc. Clamp the piece if possible in a vice and use steady, even pressure..If you don't see metal chips spiraling out or metal chips building up..its not cutting

[lji372]

Small drills can quickly round off the point and thus just rubbing and work hardening the piece. A good sharp drill should drill thru angle iron easily. Definitely use cutting oil, even wd40 and center drill it so the drill has a place to start since it is small. Many brands are decent, but make sure it is for metal..Irwin, Cleveland twist drill, Hertel, Vermont american, Precision twist drill, Milwaukee and many others. Titanium drills are actually TIN coated and usually gold colored which helps with tougher materials, tool steels and gummy materials like brass etc. Clamp the piece if possible in a vice and use steady, even pressure..If you don't see metal chips spiraling out or metal chips building up..its not cutting

Plus a billion

A lot of cheap import drills are titanium coated ......
still useless.
Cobalt is awesome but overkill for angle iron which is about as soft as steel gets

Also, a short (stub) drill will work best if your not used to using them

Good luck

[SC Cheesehead]

Any high speed drill bit should work providing it's sharp. Drilling thru steel requires slower drill speed for good progress and like someone said some lubricant can't hurt. Motor oil will work but it's going to smoke the place up. Can't remember what we used to use in the shop.

Are you using a drill press? Trying to drill though thicker steel with a hand drill and tiny drill bits will usually get you lots of broken bits as they snap easy if they are torqued latitudinally.

Slow and steady Bob, works every time. (TWSS)




PS Please wear eye safety glasses :cool: as a chip of steel to the eye is not pleasant and potentially disastrous.:beer:

^^^^^ Yup.

[Joe Walsh]

As others have said Bob....

Slower speeds, not a lot of pressure/force and a drop or two of oil make a drill cut into steel with no problems.
If you are doing it right you can even carve beautiful (and sharp!) spiral ribbons of steel out as the drill bit progresses.