Good Drill bits for Steel

[tomstin]

I'm on the search for good drill bits for steel. The backstory, wife purchased two light fixtures for the front of the house. We were looking for dusk to dawn, but the fixtures she likes do not have that feature. No worries, drill a hole in the fixture, install a dusk to dawn sensor and we're done...until I wasn't!

I threw every drill bit I have and only scratched the surface of these fixtures. Started small and slow, tried larger and slow, small and fast, larger and fast...nothing worked. Maybe I work hardened the spot, same result on the other fixture. Okay, like you I imagine, none of these drill bits are new. They have all done a fair amount of work. Off the HD and purchased Milwaukee bits labeled for hard steel. No joy, same result.

The fixture box, appears to be powder coated stamped steel, but it must be some tough stuff.

Electrical box is in the brick wall without access to the back. I was considering a more robust solution by installing a sensor in the circuit for the fixtures, but can't get access to the wiring other than in the box. Also, considered a smart switch but the switch is in a 4 gang box and there is not a lot of space to work and need to check if there is a neutral in that box.

 

[rockettauto]

Sounds like it could be stainless, or could it be flexing too much to bite, or both. Could always just use a carbide ball.

 

[cmandp]

I always use step bits for sheet metal when I've added holes in light fixtures. I've found they are tough steel most of the time. I assume it either the alloy or from cold working to form them.

 

[gearhead1]

I’ve had good luck with an Irwin step bit.

What size hole? Can try a hole saw….

https://www.garagejournal.com/forum/threads/old-bed-frame-projects.392838/ Look at post #16 and post #31. I wonder if the metal is something like that.

 

[RTM]

Got a hole punch? But that requires a starter hole too. Hmm

 

[NoahG]

U.S.A. made is usually best, something from Norseman. My local counter stocks Blitz and those are very nice as well.

The cobalt Milwaukee bits from the Depot are pricey but worth it in a pinch. I had to settle for those the last time I was in a bind and needed to drill a bunch of 3/16” screw clearance holes in some 1/8” stainless.

 

[GeoBruin]

These have become my go to for a lot of things, including sheet metal. Astro offered a BOGO to forum members here when they first started selling these and I picked up a both the full set and the smaller set.

Astro Tools TS29 Onyx 29pc TurboStep HSS Reduced Shank Mechanics Length 1/16" - 1/2" Drill Bit Set https://www.amazon.com/dp/B01JBJTT5W/?tag=atomicindus08-20

 

[gearhead1]

I agree Norseman is good stuff. I bought a Norseman silver & deming drill bit set and they are sharp!

Lowes carries CLE-LINE US made bits - in stock, in store.

https://www.lowes.com/pd/CLE-LINE-High-Speed-Steel-Twist-Drill-Bit-Set/1000043335

 

[Kuma601]

My experience with the box store drill bits is ok. They work though are not as good as what I get from the industrial supply houses and the cost is nearly same. I would suggest a split point 135 degree cobalt and those should do most DIY level tasks.

These have become my go to for a lot of things, including sheet metal. Astro offered a BOGO to forum members here when they first started selling these and I picked up a both the full set and the smaller set.

Astro Tools TS29 Onyx 29pc TurboStep HSS Reduced Shank Mechanics Length 1/16" - 1/2" Drill Bit Set https://www.amazon.com/dp/B01JBJTT5W/?tag=atomicindus08-20

There was a YT video of one wood-metal worker demonstrating these that I saw a spell back. Looks like a great drill bit!

 

[T45]

Our local ACE HWS sells single USA Cobalt bits, may be a good fit for one-time "special application" project like this. Cost is very reasonable cost. I think they were cheaper than the Milwaukee HSS last time I looked. Worth checking out. Maybe pre-pandemic pricing still or NOS...so YMMV.

 

[ThePostman]

Norseman 135 split point cobalt bits. Fastenal is where I get them, usually cheaper by far in person than online. I use these for drilling out just about everything in the automotive world. Your other option mentioned that works wonders was the carbide die grinder bits. I bought them off the Mac truck on sale and with a lifetime warranty, but they are all rebranded from I forget who, I wanted the warranty. Snappy sells them under blue point with no warranty. They chew through steel with a scary easiness.

4-PC. Multi-Purpose Carbide Burr Set

For use with 1/4" high-speed grinders .Removes burrs from sheet metal or cast iron .Cleans up welding areas .Maximum RPM rating of 30,000

www.mactools.com

 

[AJHD]

These have become my go to for a lot of things, including sheet metal. Astro offered a BOGO to forum members here when they first started selling these and I picked up a both the full set and the smaller set.

Astro Tools TS29 Onyx 29pc TurboStep HSS Reduced Shank Mechanics Length 1/16" - 1/2" Drill Bit Set https://www.amazon.com/dp/B01JBJTT5W/?tag=atomicindus08-20

These. I still need to buy the full sets, but I've been using a half dozen individual sizes at Caterpillar for several months now drilling through hard as **** steel on a constant basis.

They have all held up very well. In fact, I've not even had a need to switch out to new bits.

The carbide and HSS Matco versions have also worked well.

 

[KnurledNut]

(Deleted. Replied to the wrong thread.)

 

[tomstin]

FINALLY! After visit to Lowes and about a $100 in drill bits and a Irwin unibit, I have on fixture working dusk to dawn. What an ordeal! The fixture laughed at the drill bits and unibit. The mark from all my efforts looked more like the center punch than the various bits. About to give up in utter defeat I noticed my Dremel case. A carbide tip bit managed to grind through the fixture. Then I used the new drill bits, one increment at a time to get to 7/16. In total, I probably have 3 hours into this project. Is that bull headed or determination?

Between the heat and frustration I decided to wait a day to tackle the other fixture.

Thanks for all the suggestions. On the bright side, I now have a nice selection of new drill bits!

 

[PCustoms]

Post a picture,this should not have been difficult or require stepping up every size.

 

[Dakotadadv8]

Never had issues with drilling metal, bought the best drill bits for metal, used corded drill, use tape to start it, done.

 

[JoeMcGov]

Many here would agree that a torch should have been utilized after the first hour!

 

[RoninB4]

-Something isn't right here. Either all your drills were dull, improperly sharpened, or the piece experienced work-hardening. The former often leads to the latter. You may have run the drill too fast, also resulting in work-hardening. If the fixture is thin sheet metal maybe it just deflected/flexed under pressure. Don't know, wasn't there, but even crappy Irwin drills should have worked without using every incremental size larger. For sheet metal, put a block of wood under the metal next time to back it up. If the drill flutes disappear while rotating slow down the RPM until you can just make them out. If the metal is thicker than 1/16" use some cutting fluid.

 

[whateg01]

If the drills enlarged the hole, then you may indeed have work hardened the center but running the drills too fast initially or by attempting to use drills that were dull. It's a good idea to know how to sharpen drills so you start with a sharp drill every time.

 

[uart]

If the drills enlarged the hole, then you may indeed have work hardened the center but running the drills too fast initially or by attempting to use drills that were dull.

Yep, this sounds like what happened. The light fixture was probably stainless or some other alloy that's prone to work hardening.

This happens to me sometimes. Underestimate the material I'm drilling and start at it with some cheap or dull bit that's not up to the job, next thing you know it's work hardened and even my sharpest drill bits wont cut it. Something I find really useful in these situations is a simple spear point carbide glass bit. High speed and low pressure, a bit of lube, and it will get through that work hardened layer in a few seconds and normal drilling can be resumed.

 

[MarineScott]

Check out Drill Hog, warrantied for breakage and sharpness

 

[milkovich]

Viking /Norseman Vortex tip. These work great in a hand drill when you can't take the part to a drill press.

 

[tomstin]

To close this project out. Second fixture took a total of 15 minutes including set up and clean up! Using the grinding bit with the Dremel got the hole started. Then the new CLE-Line bits managed to open it up. It appeared the bits would cut well with the flutes but not the tips. Also cut in small pieces versus the long strings you would associate with a sharp bit.

I've drilled through a lot of steel over the years. And never had so much trouble drilling a hole!

I couldn't get the fixture in a vise or on the drill press due to it's shape. I was waiting to slip with the drill of have a bit grab the fixture and spin it into a body part.

I considered work hardening as mentioned in the original post. Tried three other spots on two fixtures, same result.

Also mentioned in the original post, some of the bits were old, the new bits from Milwaukee, Dewalt, Irwin, CLE-Line could not get the hole started. I don't want to add up what I spent on bits to get this done, easily over $130! Now I have a selection of new drill bits! Buy a tool to make the next job easier!

These are not box store lighting fixtures. They are powder coated, and my guess, made of stainless steel. Whatever it's made of, it is TOUGH stuff.

Thanks for the help!