To choose the best drill bit you should understand the working conditions: the kind of the material, efficiency requirements, drill characteristics, etc. That is why there is a great variety of high-quality drill bits available.
Of course, the work is going to be as good as what you put into it. High-quality bits work are more accurately sized and usually work for a longer time in comparison to low price ones.
Most of the drill bits are now made of high speed steel alloys. A good HSS drill bit will last pretty good if you run it at a slow rpm and proper feed rate. HSS with an addition of cobalt have greater heat hardness and it is more durable. “Cobalt” drill bits are more brittle, but stay sharp longer and they are able to drill stainless or hardened steel much more efficiently, than plain HSS bits.
Both “cobalt” and HSS drill bits could have coating made of titanium nitride, oxide or other. The coating helps to remove the heat from the cutting edge and helps to drill faster.
When using in hand drill, coating is not so important, because you can’t control feeding and vertical force. All you need is to use cutting fluid or oil (water) and use low speed.
Drill bits are expendable items, you need to sharpen them as they dull. Don’t work with a dull bit, it will overheat and the steel will degrade.
We’ve prepared a short comparison table to help you to choose the right product.
14-Piece Titanium Drill Bit Set – 1/16, 5/64, 3/32, 7/64, 1/8, 1/8, 9/64, 5/32, 1/2, 3/8, 5/16, 1/4, 7/32, 3/16 In.
These bits have a titanium coating that decreases friction and helps to remove heat, providing (amazing) up to 6 times longer life in comparison with standard high-speed steel bits.
These set is pretty good, even under very heavy use. The case is heavy duty and lives as long, as the bits do. For home use they will remain sharp almost forever.
Brad points bits are very good at start. The tip helps to make cleaner holes without “walking”.
The price for the set is about 40% lower compared to buying one-by-one separately.
Irwin Tools 3018002 Cobalt M-35 Metal Index Drill Bit Set, 29 Piece
This is cobalt high-speed Steel Drill Bits set in 29-Piece Metal Index Set. Sizes are in the range from 1/16″ up to 1/2″ in.
The set comes in great rubber overmolded case, it has convenient bright size markings. You can remove cartridges to choose needed bit. Lock mechanism seems to be a little weak, but works
Drill bits are 5% cobalt (3018002), IRWIN has bits which are cobalt 8% (3018002b), they are better, but more expensive.
Heat and abrasion-resistant cobalt alloy makes this set one of the best quality drill bits for drilling stainless steel. It is way more expensive than regular HSS Dewalts, but if you work with hardened, stainless steel or another “exotic” metals – cobalt Irwin bits drill like a hell – “suitable for drilling armor”.
Important! Cobalt bits are brittle! You can drill any material, but don’t choke up on the bits or they will snap even in soft wood.
A tough cobalt alloy delivers heat resistance up to 1100 degree Fahrenheit allowing, extended periods of time without failing due to the high heat levels.
Overall bit hardness of 66-68 HRC gives the ability to penetrate exceptionally tough materials.
Withstands high-temperature applications for extended periods of time (up to 1,100°F)
These are maybe the best quality drill bits for drilling in hard steel.
Successfully used for drilling into light-gauge metal, high-carbon steel, aluminum and alloy steel, cast iron, stainless steel and titanium.
It has a reduced shank to fit a 3/8 chuck, stamped HSS-Co, which indicates M42.
A bit pricey, but worth it when you need to work with tough steel.