As a DIY enthusiast, it is quite appealing to have a complete set of tools in your kit. Not only will this make your work easier but also gives it a professional look. Does that sound like something you want to reckon with? Of course, one of the things that are nearly inevitable while working on a simple project or task is drilling holes, but have you been doing it correctly?
Anyone could pick up a drill bit of a desired shape-type and start drilling holes. However, selecting and using the right type of drill bits on a target material is another thing to know, otherwise, you risk damaging the working material. Fortunately, drills of varying materials, sizes, and shapes are made available by their manufacturers and you could select any depending on your needs.
Let’s go over the different types of drill bits and how to use them.
1. Auger Drill Bits
Boring large holes in woods and thick man-made boards requires the use of more powerful drills than twist drills. Ideally, Auger drill bits are used for this purpose and do not require the application of unnecessary pressure; they should be driven at a low speed but high torque (preferably, 600 revolutions per minute) for a desirable result. If your using a drill that has a dual speed gear box, make sure it is engaged in the lower speed range. This will deliver more torque and enhance your control while drilling.
As a heads up, drilling with Auger bits is likely going to give you an unclean result because when the bit’s tip begins biting into the wood, it pulls the remaining parts into it causing it to chip the wood. However, this can be avoided by placing a piece of “painters’ tape” over your desired spot before drilling. Also starting your hole slowly (low speed) will provide a cleaner edge, once below the top of your material, you can speed up.
2. Spade Drill Bits
Spade drill bits are also referred to as flat or paddle drill bits, they are designed to work with a power drill or cordless drill to bore deep and fairly wide holes. Although the bit’s head is flattened, the specialized spur tips are designed for clean fast starts.
During usage, as you near the bottom of your hole, spade drill bits will produce shattering of the backside as it exits your work piece (also referred to as “blow out”) However, a sacrificial backing board can be used to minimize the effect by placing it behind your working piece.
It should be noted that unlike twist drills, more torque is required by spade drill bits and if you are not an expert, it’s recommended not to make an angled hole with it as you may encounter difficulty doing this.
3. Glass/Tile Drill Bits
As the name implies, these drill bits are meant for drilling holes in ceramic, glass and tile. The tip of these drill bits is made of rigid tungsten carbide. Hand drills can be used for operating the glass/tile bits, however, power drills work well at slow speeds.
Due to the rigidity of the carbide, the application of lubricant (water is recommended) to keep the tip cool and cutting, also minimizes dust. Once again, due to the hardness of the material at the tip, glass bits are not easy to sharpen once blunt but an oilstone would still do this.
4. Titanium Drill Bits
These drill bits are ideal for drilling through plastics, woods, and metals faster. Compared to other types of drills, they have a longer lifetime and the titanium nitride coating is responsible for this. Apart from being responsible for its durability, the coating also ensures that materials like aluminum do not stick to the bit.
After prolonged usage, they could become blunt and might not be useful unless they’re recoated. It is, however, advisable to replace them instead of recoating.
5. Cobalt Drill Bits
Cobalt drill bits are made from an alloy of high-speed steel and cobalt, and are best suited for large volumes of metal work as they can resist abrasion and tremendous heat produced by these metals. The Cobalt alloy creates a high-performance structure that can bore through hard materials like stainless steel and titanium. They can also be used to drill through all kinds of surfaces, including plastic, wood and most metals.
If the material your working with is a hard metal like stainless steel or cast iron, Cobalt drill bits are your best choice.
6. Black Oxide Drill Bits
These are high-speed steel bits that have been heated to a high temperature to give a result that is resistant to corrosion and rust. Because of this, friction is significantly reduced and the bit can be used at higher RPM’s. Black Oxide bits are tougher than the standard HSS bits and with a longer lifespan.
It can be used on a wide range of materials like various metals, woods, and plastics.
7. Multi-material Drill Bits
The multi-material drill bits are manufactured for multipurpose use, as the name implies. They are suitable for applications on woods, metals, masonry, and concrete to create clean holes with their sharp edges. The tip is made of carbide to extend durability and can serve both professionals and DIY enthusiasts.
You can use either the hammer or rotary mode, however, the rotary mode is recommended when working on masonry. The flutes are designed for fast and efficient debris removal while drilling.
8. Countersink Drill Bits
Countersink bits are used to form the conical recess in your material to countersink the heads of screws. They also provide a pre-drilled guide hole for your screws so that no splitting happens when the screws are installed. This is important near the edge of your work piece. These bits should be used in in power/hand drill and are ideal for use on wood, plastics and other soft materials. Not intended for metals. There are special metal counter sinks for this purpose.
9. SDS Drill Bits
SDS bits are very effective for working on dense materials. Such work pieces include stones, and masonry products like concrete and block. The two most common variants include SDS-Plus and SDS-Max. Both of these shank configurations have specific tools that only accept either. SDS Plus covers smaller diameter bits ranging from 5/32 up to about 1”, whereas SDS Max bits can go from 1” up to 6” in diameter. Bit lengths can vary from 6” long to over 60” from some manufacturers.
Both bits of this style use a hammering action to chip away the concrete will spinning to eject the dust and clear the hole.
There are also scrapers and chisels available in this bit style for various types of demolition work.