Replacing a drill bit takes about 10 seconds once you know the motion. You grip the chuck (the cylindrical piece at the front of the drill that holds the bit), open it, swap the bit, and tighten it back down. The exact steps depend on whether your drill has a keyless chuck or a keyed chuck, but neither method is complicated.
Before You Start
Disconnect the drill from its power source before changing the bit. For a corded drill, unplug it from the outlet. For a cordless drill, remove the battery pack. OSHA lists this as a standard safety requirement when changing accessories like blades, bits, and cutters. It only takes a moment, and it eliminates any chance of the drill activating while your fingers are near the spinning jaws of the chuck.
Keyless Chuck: The Most Common Type
Most cordless drills and many corded models sold today use a keyless chuck, which you tighten and loosen entirely by hand. No extra tools needed.
Hold the drill firmly in one hand. With your other hand, grip the outer sleeve of the chuck (the ridged or rubberized ring at the very front of the drill). Rotate the sleeve counterclockwise. You’ll see three metal jaws inside the chuck begin to open as you turn. Keep rotating until the jaws are wide enough to release the current bit, then pull the old bit straight out.
Insert the new bit into the center of the open jaws, shank end first. Push it in far enough that the jaws will grip a good portion of the shank, typically at least half an inch. Then rotate the sleeve clockwise to close the jaws around the bit. Tighten it firmly by hand. Give the bit a gentle tug to make sure it’s secure.
Keyed Chuck: Older Drills and Bench Models
Some corded drills and drill presses use a keyed chuck, which requires a small T-shaped tool called a chuck key to open and close. The key has a gear-toothed tip that meshes with teeth on the outside of the chuck body.
Insert the chuck key into the hole on the side of the chuck so the teeth interlock. Turn the key counterclockwise to open the jaws. Remove the old bit, insert the new one, then turn the key clockwise to tighten. Most keyed chucks have two or three holes spaced around the chuck body. For the most secure grip, tighten using at least two of these holes in sequence. This ensures all three jaws apply even pressure on the bit.
Always remove the chuck key before turning the drill on. A key left in the chuck will fly out at high speed the moment the drill spins.
SDS Chucks: Hammer Drills and Rotary Hammers
If you’re using a hammer drill or rotary hammer designed for masonry work, it likely uses an SDS-Plus or SDS-Max chuck. These don’t have tightening jaws at all. Instead, the bit locks into place with a spring-loaded collar.
Pull the collar toward you (away from the drill body) and hold it. Slide the old bit out. To insert a new SDS bit, pull the collar back again, push the new bit in until it clicks, then release the collar. Give the bit a tug to confirm it’s locked. The grooves machined into an SDS shank engage with ball bearings inside the chuck, so the bit can move slightly in and out during hammering action. That movement is normal.
Matching the Bit to Your Chuck
Not every bit fits every drill. The shank, which is the smooth end that goes into the chuck, has to match what your chuck is designed to hold.
- Straight shank: The most common type. A simple round cylinder that fits standard three-jaw chucks on regular drills. Compatible with most handheld and bench drills.
- Hex shank: A six-sided shank that prevents rotational slippage. These fit into quick-change chucks and impact drivers. Many hex-shank bits also work in standard three-jaw chucks, but not the other way around.
- SDS-Plus and SDS-Max: Specially grooved shanks for hammer drills and rotary hammers. These only fit SDS chucks and are not interchangeable with standard chucks.
Check the maximum capacity stamped or printed on your chuck. Consumer drills typically accept shanks up to 3/8 inch or 1/2 inch in diameter. If you try to insert a bit with a shank larger than your chuck’s capacity, the jaws simply won’t close around it.
Getting the Bit Seated Correctly
A poorly seated bit wobbles during drilling, produces oversized holes, and wears out faster. When you insert the bit, make sure it sits centered between all three jaws before you tighten. If the bit is resting against one jaw and not touching the other two, open the chuck slightly and reposition it.
Tighten gradually rather than all at once. As the jaws close, you can visually check that the bit looks straight. Once tight, hold the drill at eye level and look at the tip of the bit. Spin the chuck slowly by hand. If the tip traces a small circle instead of staying in one spot, the bit is off-center. Open the chuck, reseat the bit, and try again.
One common mistake is not inserting the bit deep enough. If only the very end of the shank is gripped by the jaws, the bit can slip under load or even fly out. Push the shank in until it bottoms out or until a substantial length of shank is inside the chuck. For standard twist bits, the fluted (spiral) portion should begin just outside the chuck jaws, not inside them.
When the Bit Is Stuck
Bits sometimes get stuck in the chuck, especially if the chuck was overtightened, exposed to dust, or hasn’t been opened in a long time. For a keyless chuck, try gripping the sleeve with a dry cloth or rubber jar opener for better leverage. Rotate counterclockwise with firm, steady pressure rather than jerking it.
For a keyed chuck, insert the key and tap the handle gently with a rubber mallet to break the grip. A drop of penetrating oil around the jaws can help if corrosion is the problem. Let it sit for a few minutes before trying again.
If your drill has a forward/reverse switch, you can also try this: set the drill to reverse, hold the chuck sleeve firmly so it can’t rotate, and pulse the trigger very briefly. The motor’s torque works against the stuck jaws and usually breaks them free. Only do this with the battery installed (not removed) and keep your hand well clear of the bit.