Drill Bits

[markgrubb]

[abcollector]

What it comes down to is you get what you pay for. Buy cheap = inferior product. Yes, it does happen that once in a while the planets line up, the tide is high and the moon is at the precise degree location and your cheap product was spectacular. You can't count on it. If you demand precision, don't go for the blue light special.
Having said all that, generally available drills aren't sharpened correctly from the factory from the get-go. If a drill doesn't cut a round hole, the point is not centered, one lip or cutting edge will be longer than the other.
Harbor Freight doesn't scream quality but if you're bargain shopping, that's what they're there for.
Nitride or any coating on a drill for general use is a gimmick and is a waste of the extra cents it cost over a bright or black oxide finish.

[markgrubb]

What brand is quality? Most holes appear tri-lobed.

[baih777]

DO NOT buy HF drill bits.
there junk.

I use the Dewalt cobalt drills a lot.
the common drills I use the most, I buy 10 at a time from Mcmaster Carr

and no drill bits don't make a perfect hole.
I use reamers.

[hermosabeach]

HF are not good

For thin materials, the step style sheet metal bit is better than a twist bit as it does not tear out the material
The HF ones are great for $14/2. Good step bits are $45& up

If you want a round hole- use a mill

If you want a decent hole- a pillar drill/ drill press

It all depends on the specs of the work.

Milwaukee and dewalt make good bits

Hard bits are too fragile to use in non hard material. I’ve broken too many cobalt bits when I really did not need to be using a great bit.

[hermosabeach]

The sheet metal / step bit

[hermosabeach]

And the expensive version

https://www.mcmaster.com/metal-drills

[RustyIron]

I work on a lot of composite German aircraft.

You build or repair aircraft, yet you need advice on what general purpose drill bits to buy? Color me intrigued.

Generally, you can't expect to get precision holes with a drill. So just forget about that. Reaming a hole might get you what you want, or better yet, boring the hole.

What exactly are you trying to do?

[markgrubb]

Uhhh, drill better holes?

Was curious as to what I might learn or if I had missed any evolution in drill bits. So far, nada.

[wickeditr]

What HB said. Get yourself a proper drill index from McMaster. Airplanes and fractional bits...? Say what? Browntool.com is a good place for proper tools. Watch out for the imported stuff though.


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[wickeditr]

Also, check the drill and operator. Bomb sighting and drill guides also make better holes.


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[ar15barrels]

Uhhh, drill better holes?

Better holes come from a more rigid setup.
Round holes come from boring, reaming and honing.

Holes made with 2 flute drill bits don't come out round because the 2 flute design is not self centering.
A 2 flute drill bit wanders around as it cuts.
You need more than 2 flutes to get a round hole.
3 or more flutes dramatically reduce the ability of the bit to wander within the hole that is being drilled.

[markgrubb]

Agree that McMaster rocks, especially the aviation section. Always the best stuff but somewhat expensive. Brown tool, not so much in my experience.

Reread original post. General shop use as well as aircraft. German aircraft are almost all metric fasteners. If not metric, then fractional. No numbered sizing.

Let me rephrase my Simple question:

What brands and sources do you prefer for quality drill bits sets at decent prices?

[ar15barrels]

Let me rephrase my Simple question:

What brands and sources do you prefer for quality drill bits sets at decent prices?

Stick with USA made tools like Triumph, Chicago Latraobe, L&I, Greenfield etc...
Different materials will require different geometry tools.
You will NOT find one drill bit that works well in all of those materials.

Get a GOOD drill bit sharpener and you will not need to buy very many more drill bits as you can re-sharpen good quality bits over and over until they are too short for your use.

[markgrubb]

AR15: Thanks for the cogent explanation! Truly appreciated.

What brand and source do you prefer for general use?

Thanks Again!