The majority of drill bits contain the same basic parts. A typical drill bit consists of a shank, lips, flutes and a tip. The shank is the part that is placed inside a drill chuck. The lips are the cutting edges and the flutes are the grooves in between the lips that allow material to exit. Finally, the tip is the business end that is placed against the material for maximum cutting.
Drill Bit Sizes
Drill bits come in wide range of sizes and are measured at various points on the bit. The bit diameter refers to the size of the tip while the shank diameter measures the diameter of the shank. These measurements will tell you how large a hole the bit will make in the material and whether or not it will fit in your drill. Drill bits are also measured in total length and length of the flute, which determines the maximum cutting depth.
Types of Drill Bits
Drill bits are designed to fit a wide range of applications. Twist bits are easily the most common types of drill bits on the market. They are great for general use and work well with metal projects. Brad point bits are better suited for woodworking projects because their sharp tip enables self-centering. Forstner bits are designed to drill large holes in wood while split point bits are best used for metal drilling. There are many more types of drill bits on the market, each one specifically designed for different material and uses.
Carbon Steel Bits
Drill bits are most commonly made from carbon, both low and high grade. Carbon bits work great on soft materials, such as wood and plastic. These bits can be used on metal, though they will wear out and dull quickly. If you have a lot of metal drilling to accomplish, consider using a higher grade steel bit for maximum effort.
High Speed Steel Bits
Unlike regular carbon bits, high speed steel bits are hardened through a tempering process. This enables the bit to drill through harder materials, like metal. While high speed bits can cut through some metals, too much heat can damage the bit and make them ineffective. For hard metals or long periods of drilling, cobalt bits are preferred.
Cobalt Steel Bits
Cobalt bits contain a mixture of cobalt and steel alloy. These bits are harder than the high speed variety and are able to navigate through high temperatures. Not only can cobalt bits drill through harder metals than their high speed equivalents, but they also last longer when used on hard materials. The only downside to cobalt bits are their brittleness, especially when they are not used correctly. They are also more expensive than high speed or carbon bits.
Titanium Coated Bits
Titanium bits are high speed steel bits coated with titanium nitride. This coating makes the bit incredibly hard and resistant to corrosion. Titanium bits are more costly than high speed bits but they last up to five times longer when properly used. One disadvantage to titanium bits, however, is that they cannot be sharpened and retain their coating.
Like titanium, carbide bits are extremely hard. These bits can cut through some of the hardest of metals, including stainless less, without great loss in performance. There are many downsides to using carbide bits. Not only will they hurt your budget, but they are not recommended for use in hand drills or drill presses. Carbide is also very brittle and should only be used for drilling through the hardest of material on the market.
Selecting the right drill bit for your project depends on a number of different factors, including type of material, diameter of hole, and depth of cut. When selecting the right kind of bit, start by choosing the best bit for whatever material you are working. Then, think about what kind of hole you need to drill and choose the appropriate type of bit.