Now that we have gone through the different types of drill, let’s see what features make them different.
Normal and SDS drills
Most hammer drills require SDS drills. These are placed in the chuck on the mandrel, which allows the propulsion in front of the drill.
To drill without percussion? You need a normal drill. Some drills have a separate chuck for this. But for most drills, you put an adapter on the SDS chuck, which is inconvenient and makes the machine heavier and more difficult to control.
Size and weight
The size and weight can vary greatly. Some big drills weigh more than 5 kg! this is too heavy for long periods of drilling. Also think about size: small drills are more confo and easier to use in small spaces.
The chuck holds the drill (the tip that makes the hole). Modern drills have keyless mandrels, very practical. Most models have drills with diameters between 0.5 and 10mm or 13mm.
Look for a drill with more than one gear. Most modern drills have two. The former gives low speeds and a high torsional force for screwing, the second gives high speeds for rotary drilling. If a drill has a single gear, it will surely not perform as well for drilling as for screwing.
Cordless drills come with different twisting parameters, so you choose the twisting force for each gear, which is convenient for screwing since it avoids over-tightening or damaging the screw. Few wire drills allow you to do this.
Use the high twist for the big screws – if you’re not sure start at the bottom and go up. The number of parameters goes from 6 to 31! There is little chance of needing 31 parameters, but it helps to have a choice.
If your torsion parameter is well defined, the chuck should stop when the screw is flat on the surface.
The design of the handle
Drills with a T-handle center their weight, making them more balanced. Do not hesitate to do your tracking in store to compare the grip. A second screw-on handle can be handy for balancing weight and giving you better control.
If you buy a cordless drill, you will have to take the voltage into account. In general, the higher the voltage, the faster the completion of the task, and the longer the operating time of the drill without overheating or fully discharging.
But the drill still needs to convert power. A drill of 18V or more is useful for large drilling, which can quickly empty a small battery.
Nowadays, most drills recharge in an hour or less. But some take up to 5 hours. Fortunately, lots of drills come with a second battery, to use while the other charges.
If the drill you choose has only one battery, consider buying a new one. This will save you from having to stop if one of the batteries gets discharged.
Li-ion batteries are becoming more common and offer good energy storage for cordless drills. Nickel calcium (NiCd) batteries do not have the same storage capacity as Li-ion batteries.