Quality drill bits for metal.

[N80]

I don't work with metal much but from time to time I do and seem to be doing more than usual lately. My Harbor Freight drill bits and the pile of drill bits I inherited from my Dad are not getting the job done. Lots of work. Holes not pretty. I know they can be sharpened but even when sharp they only last a minute or two and even then don't cut all that well.

I recently came across a 'good' drill bit in the pile of old bits from Dad. All the markings were worn off of it so I couldn't tell what it was. It was old and well used but did a far better job and for a lot longer than anything else I have.

So the assumption on my part is that some bits are better than others both in cut quality and ability to hold an edge. My question is, is there a specific brand of bits that would be worth the money for a part timer like me for general drill press and hand held drill work? I do not need a wide variety of sizes. I'd be willing to pay for quality.

 

[Menagerie-Manor]

Over the years buying and collecting drill bits I've found the DeWalt pilot point bits tend to hold up well for me. I several common sizes that I bought in bulk packs. I stopped buying 1/8" bits for common pilot holes and switched to 3/16" dia. that hold up a lot longer.

 

[Moxie 15]

two rules
1. half the speed double the feed
2. keep cutting edge cool
figure these out and even "junk" bits will drill through steel

 

[jjeff]

Bits made with Cobalt work great for metal work. They are however more brittle imo.

 

[N80]

two rules
1. half the speed double the feed
2. keep cutting edge cool
figure these out and even "junk" bits will drill through steel

Agree. My junk bits make it through. But it is a lot of work compared to a 'proper' bit. Having said that, some of these junk bits after a few minutes work will not cut at all. You can sharpen it and go again...but that's a process that gets old and tiresome too.

 

[Root Cause]

M2 is quality high-speed steel and is commonly found in machine shops.
Titanium-coated cheap steel is what HF sells, it is crap, and you can't sharpen them.

For small bits (under 3/16) I run them pretty fast and with little pressure and some oil. If you have to push hard at all, you have a dull bit.

Go to MSC, Grainger and buy a dozen greenfield or the other USA-made bits. Get a bit sharpener or learn to sharpen them by hand on a snag grinder. You can make them last years if you get them so hot that you temper the hardness out of them.

 

[ArlyA]

Bits made with Cobalt work great for metal work. They are however more brittle imo.

When I need a bit to last and stay sharp, I get kobalt ones. Its a fancy version of HHS but its worth the extra cost in my book (still a amateur). Sharp bits are your friend.

 

[arto98607]

I just recently bought Drill Doctor 750X and have used it couple of times to resharpen older US or European made drill bits with pretty good success!

Sharpening drill bits manually used to be pretty easy for me but it's gotten harder since my eyesight is not improving.

Aren't the small kit Milwaukee, Bosch and DeWalt bits all made in China nowadays?





I bought this $150 Taiwanese drill press over 30 years ago and it has worked alright, I just wish it had a variable speed drive.

 

[etpm]

Precision Twist Drill is a good brand. More expensive but well worth it are Guhring brand drill. Drill bits come in all sorts of lengths but the two most common lengths are Jobber length (long) and Stub length (short) (duh). Stub length is also called Screw Machine length. It is best to use split point drill bits. Split points are very common in Stub length but can also be had in Jobber length.
Cobalt HSS drill bits will last longer than regular HSS drill bits. The gold colored coating found on some is titanium nitride. If done properly this coating is very wear resistant, but the cheap drills with it have such a thin coating that is is really no help at all.
The split point helps to center the bit so that it doesn't tend to wander and it also requires less pressure. In my machine shop I use almost exclusively split point cobalt stub length bits. I only use the longer Jobber length bits when needed.
When drilling steels you should use cutting oil, NOT regular lubricating oil. That means don't use motor oil, ATF, 3 in 1, etc. A half way decent hardware store will have threading oil. It may be clear or brown. It really won't matter much which you use. They will both contain sulfur, which is a high pressure lubricant.
When drilling aluminum you can use kerosene, or lamp oil (which works just as well and doesn't stink), or most any light oil. It is usually best if the lamp oil is mixed with a little of regular cutting oil because it will stick the the drill bit better.
There are all sorts of drill speed charts on the internet. Use the right speed. Running the bit too fast makes it get too hot and this ruins the cutting edge fast. It is way better to run the bit too slow rather than too fast. Make sure that the drill is always making a chip. If it stops making a chip it is being ruined. When drilling stainless slow speed and high pressure is the method that will make the bits last longer and also will let the drill go all the way through the part being drilled.
Eric

 

[MossRoad]

When I was pretty young, someone showed me how to sharpen bits on a bench grinder. I still do that to this day. If I need a new bit, I try and buy name-brand. I've had my share of Harbor Freight bits... the best thing I can say about them is I like the organizer they come in.