Having the right drill bits for the task at hand can make all the difference in how your project turns out. Trying to drill a hole through wood using the wrong bits can be difficult, and the end product can be aesthetically unpleasing at best, and dangerous at worst. Drill bits need to be sharp, and if you need to apply extra pressure to drill it through, you should consider another drill bit, as the one you’re trying with may be dull, ruining your project or damaging your drill. That being said, there are a few things to consider when choosing from the thousands of drill bits available nowadays, the most important of which are:
Material and Finishes
The materials drill bits are made of and the finishes applied to them are the two major deciding factors for their performance and longevity. The most commonly used materials and finishes are:
Cobalt Drill Bits – These are very durable and have extraordinary heat-dissipating abilities. Cobalt bits are used for boring rigid materials, such as aluminium and stainless steel.
High-Speed Steel Bits – These bits are capable of drilling fibreglass, wood, soft metals and polyvinyl chloride.
Titanium Coated Bits – These bits produce less friction, are tougher than high-speed steel bits and stay sharper for longer. They’re ideal for drilling through virtually any type of material.
Black Oxide-Coated High-Speed Steel Bits – These feature a finish that’s specifically tailored for extra corrosion resistance and improved durability. They’re superior to high-speed steel bits, but inferior to titanium coated bits. Black oxide bits are suitable for use in metal, softwood, fibreglass, PVC and hardwood applications.
Carbine-Tipped Drill Bits – These bits stay the sharpest and can drill through masonry and tile, making them the toughest out of all bits.
In most cases, the angle of the point determines the type of material bits can drill through. Those with a 135° angle, for instance, are better suited for drilling hard materials. However, they may require a pilot hole to prevent the bit from wandering. Bits with steeper points, on the other hand, like those with 118° angles, are better suited for softer materials. They’ll stay on-centre and create cleaner entry and exit holes. Those with split point tips will prevent the bit from wandering and improve drilling accuracy. Using bits that are compatible with the drill can also help with accuracy and cleanliness. For instance, Alpha drill bits are best used with Alpha drill tools.
Furthermore, the bit size can make a huge difference in which bit is ideal for your task. The size refers to the diameter of the bit body. Some projects require bits of specific sizes, but a bit set that includes the most common sizes will work best for the majority of workshop and home applications. Of course, you can always add to the set should you need bits of different sizes not included in the set. Smaller drills suitable for home improvement projects generally feature a 3/8-inch chuck. Drills suitable for heavier applications feature 1/2-inch chucks. Drill presses also feature large chucks, generally 5/8 or 1/2 inches. The bit shank size shouldn’t exceed the drill’s chuck size. A large bit, however, may feature a reduced shank, which would be smaller than its body, allowing you to use it with smaller chuck drills.
Lastly, the shank of the bit also plays a role in performance. Round shanks allow you to centre the bit in the chuck more accurately. On the other hand, a hex shank features a flat surface, allowing your drilling tools to grip the bit better for improved torque. These shanks also work with quick-change chucks, which are commonly found on most cordless Alpha drill tools, allowing you to place and remove them without touching the chuck. Lastly, there are slotted-drive system shanks that are designed for use on hammer drills. They fit in spring-loaded chucks that don’t require tightening. These bits can be moved back and forth with the hammering motion of the drill, and flattened slots and areas on the shank allow the chuck to secure the bit.
Popular Bit Types
There are several popular drill bit types used in everyday applications, including twist drill bits, brad-point drill bits, auger drill bits, self-feed drill bits, installer drill bits, spade bits, Forstner drill bits, Hole saw bits, countersink drill bits, plug cutter bits, masonry drill bits, tile drill bits, step drill bits, drill saw bits, pocket hole bits, etc.
The Final Word
As you can see, choosing drill bits is relatively straightforward, as long as you are aware of your choices and understand the requirements of the task at hand. Drill bits are available in sets or as individual bits, and they’re manufactured by the same companies that manufacture drills, ensuring compatibility and ease of use.