Getting to Know the Parts of a Drill
Knowing the parts of a drill is key to getting the most out of it. Whether you’re a DIYer expanding your knowledge, the greenest apprentice, or just checking up to make sure we know what we’re talking about, you’ve come to the right place!
If you’re looking for parts to fix your drill, well, sorry, that’s not us.
Functional Parts of a Drill
- Power Source
- Rocker Switch
- Gear Selector
- Mode/Clutch Collar
Parts of a Drill
Most drills you’ll come across will either be corded (AC) or cordless (DC). Corded drills give you as much runtime as you want while cordless models will have to recharge.
Cordless models come in a lot of flavors. Here’s a quick breakdown:
- 4V or 8V – usually for light screwdriving in delicate materials
- 12V – light and compact, these can do as much as 80% of the work most Pros do
- 18V/20V Max – these can be compact or heavy-duty and make up the majority of what Pros use
- 36V – you won’t see a lot of these anymore, but they’re designed to have more power than 18V.
In the cordless world, nickel metal hydride (NiMH) and nickel cadmium batteries (NiCad) are pretty much obsolete, though you’ll still see some NiCad on the shelf. Lithium-ion is the latest technology. It gives the drill access to more power, longer runtimes, and doesn’t have that annoying battery memory.
4V/8V drills aside, every drill should have a variable speed trigger. This simply means that as you pull it, it gives you an increasing amount of speed and power.
The Rocker switch is what lets you switch the chuck from forward (clockwise rotation) to reverse (counterclockwise). Letting the switch sit in the middle between the two will lock it out.
Gear Selection Switch
If your drill can switch gears, you’ll usually find the switch on the top. The relationship between speed and torque on a drill is inverse – when you’re in high speed you have less torque and when you’re in low speed you have more torque.
Some drills may have three or four gears to choose from while others might have electronic controls above the battery and even Bluetooth connection to your smartphone.
Most drills have a rotating collar just behind the chuck. This allows you to select lower torque setting than the gear you’re in is capable of. The lower the number, the lower the torque, but those aren’t torque values, they’re just marked positions.
Twisting the collar all the way counterclockwise, you’ll find a drill icon. This disengages the clutch and gives you all the torque you can get in that gear setting.
If your drill has a hammering function (hammer drill), you’ll see a hammer icon one click further than drill in most cases. Some drills put that setting behind the clutch.
While there are still some keyed chucks running around, most are keyless. Simply rotate the chuck at the front of the drill clockwise to open it or counterclockwise to close it. Metal prongs inside come out and grab your bit when you tighten it down.
Some chucks have a ratcheting action. When you close it all the way down on the bit, you’ll hear it give you a few clicks of extra tightening to really secure the bit.
All those parts of a drill depend on the motor to drive things along smoothly. There are two main types – brushed and brushless motors. Brushless motors are more expensive, but give you longer life, greater power, and longer runtime.
Pros use both styles, so it’s really a matter of choosing which one meets your needs and is in your budget.
Like the drill we used in the photos? It’s Milwaukee’s 2504 M12 Fuel Hammer Drill and you can check out the review below!