Quality drill bits for metal.

[bdhsfz6]

I have a drill bit sharpener but IMO, it isn't worth the time it takes to get right.

There are good industrial quality bits out there but they're expensive. I don't do a lot of machining anymore so for bits under a half inch, I buy in bulk and toss them when they wear out.

I've had pretty good luck with these:

Amazon.com

 

[5030]

I also have an end mill sharpener that I make good use of. I quit sending them out to be sharpened a while ago and invested in one. I still send out my chucking reamers however.

 

[N80]

I agree with MossRoad. Learn how to sharpen a bit and most any brand of bit will cut just fine.

Upon reflection and watching the videos posted earlier in this thread I disagree with this. I have had two of the junk sets he tested and in some cases they simply won’t do anything even when new. Just like in the video. And for me the whole point is saving time and physical effort. Struggling with and sharpening a junk bit every time you drill a hole does not meet either of those requirements.

 

[MossRoad]

Upon reflection and watching the videos posted earlier in this thread I disagree with this. I have had two of the junk sets he tested and in some cases they simply won’t do anything even when new. Just like in the video. And for me the whole point is saving time and physical effort. Struggling with and sharpening a junk bit every time you drill a hole does not meet either of those requirements.

You still should learn how to sharpen your quality bits (and your chainsaw chains, too ). OK, that's getting old. I'll stop now.

 

[fishdrivel]

Proper cutting speed is the key to using drills.
The calculations are very complex and your drill does not tell you the cutting speed anyways.

If you are drilling at the correct cutting speed, your shavings should stay mostly in long spirals. (very hard to do with hand drill)
The following video is more entertainment than useful but will get you thinking!

 

[MossRoad]

See, some folks say spirals, some folks say chips. Which one is it and why?

 

[MinnesotaEric]

I've been using a set of Mac Tools jobber length drill bits since I was 21 years old. The first thing on the first day they taught us at Dunwoody auto-tech school was how to sharpen drill bits.

 

[PILOON]

I must have a good eye, or learned how early on, as I always sharpen all bits from about 3/16 on up.
I also frequently dress my fine grinder stone with a diamond dressing tool.
Basically I simply freehand do my grinding.
Also keep some water nearby to keep the bits cool.

Also not often mentioned is certain metals prefer different point angles for best performance and also different lubricants for different metals. (LOL, knowing that I often simply use WD40 as that is handiest)

 

[N80]

You still should learn how to sharpen your quality bits (and your chainsaw chains, too ). OK, that's getting old. I'll stop now.

All of my life's problems would be solved by learning to sharpen things.

The funny thing is that I've always been fanatical about sharp stuff. Cannot abide a dull knife, etc. As for drill bits its hard to say if I'm doing it right because most of the bits are junk bits. I'll get about as much drill time out of one after sharpening it as I did when it was new....which is not much. I think using the narrow belt sander is way easier than a grinder.

As mentioned, speed is critical and as shown in those videos pressure requirements vary with different metals and different bits. When hand drilling there is usually a sweet spot with both pressure and speed. I can't say if the shaving size or shape tells me much but I can usually feel the sweet spot. The issue is that keeping constant speed with a hand drill that doesn't lock at a set speed is hard. Constant even pressure is hard too when you're 58 years old, not exactly in tip top shape and lying in wet gravel.

 

[RoninB4]

Speed calculation is critical for the life of ANY cutter but it doesn't do much good if you can't tell the spindle speed of a hand drill or drill press. A simple "guestimation" for drill low carbon steel is to go up to the speed where the drill flutes just start to disappear. Faster than that will burn up and dull the drill. Also, if the chip/curl is turning yellow then you're going too fast. Always use a cutting fluid of some sort, even in aluminum. Even soapy water is better than none at all. Buy HSS drills, if it doesn't plainly state that they're HSS then they're just carbon steel and are cheap crap. The coated ones are also crap most of the time. Cobalt is my favorite but are more expensive. Carbide drills in a hand drill are subject to shattering in the hole and making a real problem to get the fragments out. Yes masonry drills can work but if they overheat the brazed tip can come loose and lodge in the hole. Carbide is best used in a rigid milling machine with a solid clamped workpiece and a certain procedure (ask me if you wish). Anything else is taking a risk of creating a larger problem. I have 40 years of shop experience and this is just my opinion.