A Guide to Selecting a Cordless Drill
Whether you’re a hobbyist who likes to construct things out of wood or metal, or if you want to do some house repairs or improvements without calling a handyman, a drill is practically a necessity in your home, whether you want to drill a hole or just drive in a few screws. Nowadays, there are cordless drills that have impressive battery power and battery life that can compete with corded models. And you have the convenience of being able to work away from a power outlet!
We’ll look at some features of cordless drills, and look at the various specifications that distinguish one from another. There are things like battery voltage, drill speed, torque, and clutch settings, that are worth noting before making a purchase. There are also other details like the drill’s weight and size that can figure into your decision. Let’s examine some of the specs on the Best Reviews Guide list of the best cordless drills!
What types of cordless drills are there?
The main types of cordless drills that you’ll see are those that use a brushed motor, or a brushless motor. A brushless motor drill will be more expensive, but will run quieter, with less friction, and also not generate as much heat. The tool will last longer overall as well.
You can also see drills categorized by the size of the drill chuck, which holds the drill bits in place. You’ll see ¼”, ⅜”, and ½” drills, with the smaller size chuck being adequate for home use, while the larger chuck size will be suited for heavy-duty drilling.
What is the difference between a drill and an impact driver?
Many drills also function as impact drivers. Even though you can just insert the screwdriver bit into your drill and use it that way, your drill performs differently when used in “impact driver” mode. Instead of just rotating in one direction, it operates in bursts of 50 times a second, rotating 2 steps forward and 1 step back, so as to drive in screws better without the risk of stripping the screw.
Types of Cordless Drills
We can distinguish between cordless drills by whether they have a brushed or a brushless motor:
Drills that use a brushed motor: “Brushes”, in the context of a DC motor, are electrical contacts on the fixed part of the motor. They rub, or “brush”, against rotating commutators, that alternate in polarity so as to turn the motor shaft. This is a simpler, cheaper motor design. But, due to the friction, such a motor generates heat and has a shorter lifetime. An example is the DeWalt 20 V Max Cordless Drill/Driver Kit.
The DeWalt 20 V Max Cordless Drill, with the recharger, spare battery, and carrying bag
Drills that use a brushless motor: Instead of mechanically switching polarity to get the motor shaft to turn, a brushless motor employs alternating current to vary the magnetic field. This way, the motor shaft can rotate without even touching the electromagnetic coils around it. Such a motor can achieve greater speeds while producing less friction. So, you’ll see that a drill with a brushless motor will cost more, but will be able to achieve higher speeds. You can also work with it longer each time without it getting hot, and the tool will last longer overall. An example is the Makita 12V Max CXT Brushless Cordless Driver-Drill Kit. The motor is controlled electronically to conserve the battery’s charge. That way, it will last 50% longer when fully charged, as compared to a brushed motor model.
Makita 12V Max CXT Brushless Cordless Driver-Drill Kit
What reviewers say
We went over some customers’ impressions of the cordless drill that they bought:
Time it takes to charge the battery: Many cordless drills will come with two battery packs so that you can charge one up while you use the second one. The Craftsman V20 Cordless Drill/Driver Kit will charge up fully in 60 minutes, and the charger has an indicator light to tell you when the battery is fully charged.
Light enough for someone with small hands: One woman who bought the Bosch 12V Max 2-Speed Drill/Driver Kit said that she had absolutely no problem handling the 3-lb. drill for common jobs around the house. That should be an indication that any lighter drills will be even easier to manage.
Here are some tips and features of different cordless drills, that can help you decide on a particular model:
Torque and speed: Torque in physics is a force applied on an axis of rotation, defined as force x length of the moment arm. It’s usually given in units of force x distance, such as Newton meters. But you’ll see the torque of a drill given in units of pound-inches. Torque is the force that the drill has to exhibit when it’s turning the drill bit into the material, fighting against the resistive friction that the material is producing. There is an inverse relationship between the speed of a drill and the torque it delivers: low speed means high torque, while high speed means low torque. Drilling into soft wood will require a higher speed and less torque because too much torque can cause the wood to splinter. Drilling into stone or metal will require lower speeds and more torque.
Clutch settings: The clutch settings on a drill allow you to adjust for specific jobs when you drill or insert screws. For drilling holes, the clutch should be on the highest setting and highest speed. For small screws, you want low torque, so set the clutch to the lower setting. If you use too much torque, you can damage the screw or the material into which you’re inserting the screw. For larger screws, you’ll need a higher torque setting, and a higher clutch setting, so that the screwdriver head doesn’t slip. Properly setting the clutch will also avoid stripping the screw head.
Voltage: You’ll see that cordless drills will have batteries that are either 12V, 18 V, or 20 V. Typically, the higher battery voltage will mean a more powerful drill, both in terms of torque and speed.
Size and weight: Cordless drills for home use will advertise that they’re compact and light. A smaller size drill will give you more excellent maneuverability when trying to drill in a corner. Also, a lighter drill will mean you can work longer without experiencing fatigue.
Variable speed trigger: Most drills have two speeds: 0-450 rpm, and a higher speed of 1500 rpm. The slower speed is intended for using your drill as a driver, to drive in screws, while the high speed is for drilling purposes. Look for drills with a variable speed trigger. They allow you to vary the speed of the motor depending on how hard you press the trigger. This is a desirable feature since it gives you more versatility: you’ll need different speeds to drill into different materials, whether it’s wood, metal, or stone. The general rule is that you should use higher speeds on soft materials, and slower speeds on hard materials like metal and stone.
LED light: Many cordless drills have an LED light so that you can illuminate the area where you’re drilling. This is very helpful if you’re inserting a screw into a cabinet, where the light level is limited.
We went over some of the features of cordless drills. They’re awesome for all sorts of jobs around the house, whether you have to insert a screw into plasterboard, concrete, or wood. For occasional jobs, you can settle for a cordless drill with a brushed motor. If you’re a professional, a brushless drill probably is more in order. Check out the Best Reviews Guide list. You’re guaranteed to find something that suits your DIY needs!