Answer
For metal burrs, use 120 or 180 to remove the burr, then smooth with 220, 320, or 400.
Why it happens
Cutting or drilling metal leaves raised edges that need leveling before fine finishing.
Recommended grit
Use 120 or 180 for burr removal, then 220, 320, or 400 to smooth the edge.
Wet or dry
Dry for burr removal; wet can be used for finer finishing.
Success check
The edge feels smooth and safe with no raised burrs.
What to do
- Remove loose metal debris.
- Knock down burrs with 120 or 180.
- Smooth the edge with 220 or 320.
- Use 400 for finer final prep.
Avoid: Do not leave a sharp edge after sanding.