Tools & Fabrication - Strongest Number Drill set

I just bought a 60-80 number drill set to drill through really thin aluminum (probably 1/8” thick). After snapping four of the smaller bits, I finally went to check the box to see what material they were and where they were made. The box didn’t say the material the bits were made of, it just basically said Number Drill Set 60-80 Shanghai China.

There are titanium number drill sets on eBay. I am guessing that those are the strongest that you can find. My question is, would these be less likely to break, or is a number bit going to snap no matter what if you accidentally put too much pressure on it or have it at an angle due simply to how thin in diameter it is?

I'd purchase some really good drill bits... try snap on or mac or somethign along those lines. Also, try using an automatic center punch, so you can sort of start the bit

Even if they were cheap bits, I wouldnt think you would have issues with aluminum as long as you were drilling properly (not trying to say you dont know how to drill either...). But you can almost chew through aluminum... If you are using a super small bit, you gotta go light on the pressure or you will bow the bit and it will break. If you are just drilling a starter hole, 1/16 is as small as I would go.

Also, use some wd-40 or light oil of your choice on the bit. I usually just dip the bit in some light engine oil and thats good enough for a few holes.

I picked up a set of bits from autozone awhile back. Lots of sizes, nice little case, probably $9... They have been working great.

Just gotta watch those little ones.... Need to be real light with pressure and try to keep them going straight.

Justin

P.S. this is definetly alum right? Not accidentally stainless steel? (again not tryin to insult your intelligence). I was trying to make a heat shield out of stainless before. That stuff is a PITA to work with. I sent quite a few bits to an early grave during that project.

Go to a local nut and bolt supply and get what you need on an individual bit basis. Tell them you want all american made black nitrate coat HSS bits. Would do you some good probably to put togther a small set. Grab your small ones and then a few 3/16", 1/4", 3/8" or whatever. Unless you are spending some decent money on a bit set you are getting junk. Cobalt is the hardest material you will find but not needed for what you are doing. Also, never buy something like that from Mac or Snap on. It just a generic HSS, at best, the same as you would buy locally.

I have the Black & Decker 18 piece general purpose drill bit set and Ive only broken one in 4 years, the 1/16"...which is why there are 2 of them in that kit- guess they figure your gonna break one sooner or later lol.

Cobalt bits are your best for the money(imo).If money is no problem, then go with Ti.
I think Harbor Freight has Cobalt bits for relatively cheap. My$.02

Cobalt bits are your best for the money(imo).If money is no problem, then go with Ti.
I think Harbor Freight has Cobalt bits for relatively cheap. My$.02

You do not need cobalt, those are used for tool steels, stainless, and various "hard" alloys. Home depot, harbor freight, lowes, etc, have junk. Go to the bolt supply. You will pay the same as you would buying individually, but get a much nicer bit.

You do not need cobalt, those are used for tool steels, stainless, and various "hard" alloys. Home depot, harbor freight, lowes, etc, have junk. Go to the bolt supply. You will pay the same as you would buying individually, but get a much nicer bit.

And ummmm Aircraft!!. We tear through HSS bits like there is no tomorrow.Aluminum isn't a Hard Alloy
You really sound like you know what your talking about!!.

And ummmm Aircraft!!. We tear through HSS bits like there is no tomorrow.Aluminum isn't a Hard Alloy
You really sound like you know what your talking about!!.

What alloys are you using and what hardness are they annealed to? I dont claim to know everything, just speaking in broad sense. Dont doubt that you burn up bits if you are punching all day long. Any metal will burn bits up with sustained use. RPMs and type of drill for curiousity?

I bought a set from Matco 8 years ago and they are still sharp and work like a charm.

I'm working "C" check line, and we use everything from "O" to T6, T3 and just about everything else in between..020 to .75 thickness.

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Use cobalt here. Do it, do it right the 1st time. Run into many things working on racecars & work trucks that you need the extra strength. Worth it to me.

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Use cobalt here. Do it, do it right the 1st time. Run into many things working on racecars & work trucks that you need the extra strength. Worth it to me.

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If you use bits alot or work with them, I can see it. Honestly I buy 2-3 new HSS bits as needed and am very happy with them as compared to any of the stuff you will find off the shelf. A nice 100 piece cobalt set is something I would like to have around, but dont see the benefit right now. For instance, we recently had to drill about 15,000 1/8" holes in 18 gauge paint grip steel for an architectural project. I am pretty sure we drilled all the holes with less than 2 packages of bits. Each package has 8 bits and cost $14 or so. That was running at around 800 rpm on the press with no cutting fluid.