You're using too much pressure or no lubrication. Ease up and use oil.
- Set the tool to drill-only mode (drill symbol on the collar).
- Use a center punch to start the hole.
- Lubricate high-speed steel twist drill bits with cutting oil for iron or steel. Use a coolant for nonferrous metals like copper or aluminum.
- Apply firm, steady pressure, but if the tool stalls, reduce pressure slightly.
- Back the material to prevent binding on breakthrough.
If that didn't work, your bit is dull. Always use sharp bits. For hard materials, ensure you're using the high-speed setting (selector on '2'). Let the tool come to a complete stop before changing speeds.
Heads up: Check for hidden pipes or wires before drilling anywhere.