How To Choose The Right Drill Bit?
How do you find out what type of drill bit or size of drill you need for that project? The first thing you should know is that before an item can be drilled, you must know its exact specifications so as to choose the appropriate bits. Otherwise, if your hole is too big for the screw you are using, the result will be a poorly mounted item.
- If you’re not sure what size of a drill bit is needed for your project, start with these step-by-step guidelines:
- Measure out through the hole (if any) in your item to determine its dimensions. –Mark the center of the hole with a pen or pencil. — Measure the diameter of your marker and select a drill bit that is 1/16″ larger to ensure that the screw goes in smoothly.
- Next, you will need to choose between using a spade drill bit or an auger drill bit.
- Spade Drill Bits are best for soft materials such as wood or plastic. Auger or Twist Drill Bits are best for hard materials such as steel, stone, and concrete.
# DIY Expert Tip!
If you’re using a spade drill bit on hard material such as concrete, use a pounding action to drive it into place rather than twisting it. Once the drill is in position, turn it slowly to make the hole.
To minimize vibration, use a slower drill speed.
Meanwhile, if you are using an auger bit on a soft material such as wood, again, use a pounding action to start it and then turn it slowly into place. You may also need to pre-drill holes in harder woods where the wood is very dense.
# DIY Expert Tip!
Both auger and spade drill bits have a center tip that allows the bit to be started easily. A wood bit has two sharp cutting edges, while a masonry or concrete bit has four. Auger bits are used for larger holes in wood and masonry material. When using a twist drill bit for larger holes, you should expect to have the hole come out slightly oblong in shape. This is because wood fibers are constantly being pressed together when drilling with twisted bits.
If your bit starts to stall while drilling, withdraw it from the item and clear the chips away. Then slowly re-enter the drill until it reaches full speed again. Don’t be tempted to apply too much pressure, as this will only serve to get the drill stuck.
The correct speed is one where the bit advances smoothly and without any jerking or stopping. Depending on the material being drilled, there are likely differences in optimum speeds for twist bits or spade bits, so you should be able to find it from your instruction manual.
The last point to remember
When you are finished with the bit, it is important that you remove any burs or pieces of material left on the tip of the bit after drilling. These could cause injury if they fall off while you are using it next time. Just take some sandpaper and sand down until smooth.
