Types of drill bits and How to Use Them
1. Auger bit
Drilling large holes in wood and thick plywood requires a bit more power than a twist drill. Ideally, auger bits are used for this purpose and do not need to apply unnecessary pressure; for ideal results, they should be driven at low speed but high torque (preferably 600 rpm). If you're using a drill with a two-speed gearbox, make sure it engages in the lower speed range. This will provide more torque and enhance your control while drilling.
As a reminder, drilling with an auger bit may give you unclean results because when the tip of the drill bit starts to bite into the wood, it will pull the remainder into it, causing the wood to splinter. However, this can be avoided by putting a piece of "painter's tape" where you want it before drilling the holes. Also starting your hole slowly (low speed) will provide a cleaner edge, once below the top of your material you can speed up.
2. Shovel bit
Spade bits, also known as flat drills or paddle drills, are designed to drill deep and fairly wide holes in conjunction with power drills or cordless drills. While the head of the drill is flat, the specialized tips are designed for clean quick starts.
During use, the spade bit will produce backside shattering (also known as "popping") as you approach the bottom of the hole as you exit the workpiece, however, the impact can be minimized by using a sacrificial backing plate to place it in your behind the workpiece.
It's important to note that, unlike twist drills, spade bits require more torque, and if you're not an expert, it's not advisable to use them for angled holes, as doing so can be difficult.
3. Glass/Tile Bits
As the name suggests, these bits are used to drill holes in ceramics, glass, and tiles. The tips of these drills are made of rigid tungsten carbide. Hand drills can be used to operate glass/tile drills, however, power drills work well at low speeds.
Due to the rigidity of carbide, use a lubricant (water is recommended) to keep the tip cool and cut while also minimizing dust. Again, due to the hardness of the tip material, glass drills are not as easy to sharpen once they become dull, but whetstone can still do it.
4. Titanium Bits
These bits are great for drilling through plastic, wood, and metal faster. They last longer than other types of drills, and the titanium nitride coating is responsible for this. In addition to being responsible for its durability, the coating ensures that materials such as aluminum do not stick to the drill.
After prolonged use, they may become dull and may not be usable unless recoated. However, it is recommended to replace them rather than recoat.