What to consider: Choosing a Drill Bit Set
When choosing a drill bit set, there are a couple large factors to consider – What size holes you need to drill, and what materials you will be drilling. And whether you are a DIY who works on casual projects or are a professional contractor who does heavier duty work, having the right kind of drill bits is crucial to the outcome of your project (click for our full guide). There are three different choices of drill bits:
High-speed steel (HSS)
HHS is made for drilling into soft steels, wood, and plastic, Cobalt (HsCO) which is an upgrade from HSS that includes a 5-8% cobalt blend with the base material, ideal for drilling into stainless steel and harder steel, and Carbide (Carb), the hardest drill bit of all, used mainly for production drilling and not for hand drills or drill presses.
With HSS bits, there are three variances of compound blends, including black oxide, titanium, and cobalt. Here we examine the differences:
Black Oxide Drill Bits
Black Oxide Drill Bits are constructed by heating HSS bits to 950 degrees Fahrenheit. This creates a black oxide finish that will resist rust and corrosion, and also reduces the friction between the bit and the material, which in turn speeds up the drilling process.
Black oxide drill bits are ideal for a multitude of materials including steel, aluminum, copper, brass, PVC, polycarbonate, acrylic, oak, maple, medium density fiberboard, ABS plastic, nylon, and composite materials.
Black oxide bits are made to last up to 50% longer than standard high-speed steel bits, offering premium durability and speed, and they are considered to be the best general purpose drill bits on the market.
Titanium Drill Bits
Titanium Drill Bits are more suitable for general purpose drilling in a production or construction environment because they drill more quickly. Harder than cobalt, a titanium coating is constructed to help chips – like aluminum which tends to stick – flow through the flutes more efficiently for a cleaner drill. However, these drill bits do not have as long of a life as black oxide bits.
Once the tips are dulled, they will not regain their sharp cutting edge without again being coated in titanium nitride, so it is much more cost-effective to simply replace them rather than having them recoated. For those who want to learn more about the Cobalt drill bits, these are formed with high-speed steel (HSS) is blended with 5 to 8 percent cobalt.
These types of bits are more resistant to massive heat which makes them better suited for drilling in highly abrasive and/or hard materials like titanium, stainless steel, and cast iron. Unlike titanium drill bits that are coated with a titanium compound, Cobalt drill bits have cobalt throughout the entire material – making this ideal for hard production.
Cost and Affordability
However, due to their higher cost and durability, most professionals do not use cobalt bits for everyday or general purpose use. Their extra hardness and smaller flutes add to their total thickness and strength, and are reserved for the more productive, high-production work.