Properly inserting drill bits will help prevent them from breaking and will allow you to drill perfect holes. Drill bits are metal tools that cut materials when rotated by the motor of a power drill. They are held in the drill by a chuck, which is the rotating device on the front of the drill which clamps around the bit and holds it in place as it spins. Chucks can be keyless or keyed. Keyless chucks are opened and closed with your hands; keyed chucks are opened and closed with a small key made specifically for the chuck.

Keyless Chuck
Turn the drill's operating switch to the "off" position. If the drill has a cord, make sure it is unplugged.
Step 2
Grasp the drill firmly. Hold the chuck collar (the portion of the chuck closest to the body of the drill) with one hand and the chuck sleeve (the forward end of the chuck) with your other hand.
Step 3
Turn the chuck sleeve counterclockwise to open the chuck so that the drill bit may be inserted.
Step 4
Insert the smooth end of the drill bit into the chuck and push it back as far as it will go. If the bit is too short to be pushed all the way into the drill, then make sure that at minimum the entire smooth portion of the bit is inserted into the drill.
Step 5
Center the drill bit within the chuck.
Step 6
Twist the chuck sleeve clockwise while keeping the drill bit centered within the chuck.
Step 7
Continue twisting the chuck sleeve until it is tightly closed around the bit.