Owner’s manual
How to attach a driver to a drill?
To attach a driver bit to your Craftsman 31510411 3/8-inch electric drill, unplug the drill, open the chuck jaws with the chuck key, insert the driver bit straight in as far as it will go, then tighten the chuck securely and remove the chuck key (steps match the owner's manual).
- Unplug the drill before touching the chuck.
- Use the chuck key to loosen the chuck jaws.
- Insert the driver bit into the chuck the full length of the jaws (keep it straight).
- Tighten the chuck jaws securely using the chuck key.
- Remove the chuck key before plugging the drill back in.
- Re-seat the bit fully into the chuck jaws, then re-tighten.
- Tighten evenly; the bit should be centered, not angled.
- Use the correct size driver bit shank for a 3/8-inch chuck.
- Do not use a wrench to tighten or loosen the chuck.
| Task | Direction setting | Tip |
|---|---|---|
| Drive screws in | Forward | Start at low speed for control |
| Back screws out | Reverse | Stop the drill before switching direction |
A properly tightened chuck keeps the driver bit centered, reduces cam-out (stripping screw heads), and helps you maintain control. Unplugging first also prevents accidental starts while your hands are near the chuck.
Last updated: February 2026
What are the parts of a drill called?
On a Craftsman 31510411 3/8-inch electric drill, the main parts are the chuck (holds the bit), trigger switch, forward/reverse lever, and the motor and gear housing that drive the spindle. For the exact component names used for ordering, use the exploded view and parts list in the owner's manual.
- Chuck: clamps the drill bit or driver bit
- Trigger switch: turns the drill on and controls speed (variable speed)
- Lock-on button: holds the trigger on for continuous running (when appropriate)
- Forward/reverse lever: changes rotation direction (drill must be stopped first)
- Motor housing: contains the motor; the model plate is typically attached here
- Gear housing: transfers motor power through gears to the spindle
- Spindle: rotating shaft the chuck mounts to
- Auxiliary handle (if equipped): improves control and reduces wrist strain
If you meant the parts of a drill bit, these are the names most people use:
| Bit part | What it is | Why it matters |
|---|---|---|
| Shank | The smooth end clamped by the chuck | Must match chuck capacity and grip securely |
| Flutes | Spiral grooves | Clear chips and help cooling |
| Body | Area between flutes | Affects strength and chip flow |
| Point/tip | Cutting end | Controls how the hole starts and cuts |
Using the right names helps you match the correct Craftsman 31510411 repair part and avoid ordering the wrong component. It also helps with troubleshooting issues like a slipping chuck, a stuck forward/reverse lever, or a worn gear housing.
- Unplug the drill before inspecting parts or making adjustments.
- Do not change forward/reverse while the drill is running; release the trigger and let it stop first.
- Clamp the workpiece and use only enough pressure to keep the bit cutting.
Last updated: February 2026
How to change tip on Craftsman drill?
To change the bit (tip) on your Craftsman 31510411 3/8 inch electric drill, unplug the drill first, then use the chuck key to loosen the chuck jaws, insert or remove the bit, and tighten the jaws securely with the chuck key. Use hand pressure only; do not use a wrench.
- Unplug the drill.
- Open the chuck jaws using the chuck key.
- Insert the bit straight into the chuck to the full length of the jaws.
- Tighten the chuck jaws securely with the chuck key.
- Remove the chuck key before plugging the drill back in.
- Unplug the drill.
- Use the chuck key to loosen the chuck jaws.
- Pull the bit out of the chuck.
- Remove the chuck key and store it in the holder.
- Keep the chuck key out of the chuck before starting the drill.
- Hold the drill firmly; do not apply side pressure to “wallow out” a hole.
- Use low speed to start holes (especially on smooth surfaces) to reduce bit walking.
- Clamp the workpiece or secure it in a vise so it cannot spin.
- Wear eye protection when drilling.
| Task | Use | Do not use |
|---|---|---|
| Tighten or loosen the chuck | Chuck key (by hand) | Wrench or pliers on the chuck |
| Start a hole accurately | Low speed, light pressure | High speed with heavy pressure |
| Drilling metal | Light oil on the bit | Dry drilling until the bit overheats |
A properly tightened chuck keeps the bit centered and reduces wobble, slipping, and damaged bits. Unplugging first also prevents accidental starts while your hands are near the chuck.
For the exact diagrams and chuck illustrations (including correct bit placement), follow the owner's manual.
Last updated: February 2026
What part of the portable drill holds the bit?
On the Craftsman 31510411 3/8" electric drill, the chuck is the part that holds the drill bit. The chuck jaws tighten around the bit (using the chuck key on this model) so the motor can spin the bit without slipping; see the owner's manual.
A properly tightened chuck keeps the bit centered and secure, which helps you drill straighter holes and reduces bit wobble, slipping, and damage to the bit shank.
- Unplug the drill before changing bits.
- Insert the drill bit into the chuck to the full length of the jaws.
- Use the chuck key to tighten the chuck jaws securely.
- Remove the chuck key before running the drill.
- To remove the bit, use the chuck key to loosen the jaws, then pull the bit out.
| What you see | What it usually means | What to do |
|---|---|---|
| Bit slips under load | Chuck not tight enough, or jaws dirty | Re-seat bit and tighten with chuck key; clean jaws |
| Bit wobbles | Bit not centered in jaws, or bent bit | Reinstall bit straight; replace bent bit |
| Chuck key won’t turn smoothly | Debris in chuck jaws | Unplug drill; brush out jaws and try again |
- Never use a wrench to tighten or loosen the chuck.
- Clamp the workpiece (vise or clamps) so it cannot spin.
- Use light pressure; let the drill and bit do the work.
- If the bit jams or the drill stalls, stop immediately and find the cause.
The chuck is the connection between the motor and the bit. If it is not tightened correctly, the bit can slip, overheat, or damage the chuck jaws, and drilling accuracy drops.
Last updated: February 2026