Overview of Drill Tools

Before purchasing any drill tools it is useful to have a good understanding of the components that make up a drill, their correct names and the different features that each component can have. Let's start with a run down on the basic anatomy of a drill and how it works.

Drill Bits
Starting at the end that does the work there is the drill bit. Drill bits used on timber work by slicing thin shavings out of the wood. The rest of the drill bit i.e. the shaft is an augur (or Archemedes screw), a helical shape shape used to carry materials, in this case shavings, out of the hole. Masonry bits work slightly differently to timber bits, crushing the stone or brick as the drill bit rotates. Some drills have a hammer action to aid this crushing process.

Hello Chuck
The drill bit is held in place by the chuck which clamps onto the drill bit and forms part of the body of the drill. Traditionally the chuck was opened using a key. The drill bit was then inserted and the key could be used to close the chuck up and grip the bit tight. This was a time consuming and tedious process but luckily most drills these days have keyless chucks that can be opened and tightened by twisting with your hands. More expensive drills have quick release chucks which can be 'popped' off. The drill bit goes with it when the chuck is removed but if you're swapping between drilling and screwing, say to pre-drill a hardwood timber before screwing into it, then it is much quicker to swap between two quick release chucks. (But not as quick as having two drills!).

Pistols or egg whisks?
Looking at the main body of the drill we can see it's shaped like a pistol. This is the shape we all associate with drills these days but I can remember seeing and using hand powered drills which were more like kitchen whisks in their shape. There's still a certain satisfaction to be had from feeling the hand powered intermeshing cogs pull against each other and hearing the sound of the bit as it rips the timber. But back to pistol drills... Where the chuck connects to the body there's usually a clutch. This ring or dial adjusts the torque or the amount of power applied to rotate the drill bit. There's also a switch to reverse the direction of the rotation of the drill bit, essential when the bit gets stuck.

Powered Drill
Finally we get to the power source. The most convenient drills to use are cordless, battery powered drills. It's often useful to have two batteries. Drills, like all battery powered devices have a tendency to give out at the most inappropriate times. Also a 14v or above battery will have enough power for most DIY jobs. But if you'll be drilling a lot of stone, using a hammer action drill, then a corded drill might be best for you.

We'll take a look at different types of drill tools in more detail over the next few posts.