He was flatting the metal sheet with a hammer to remove the dents.

The flatness of the plain allowed travelers to spot distant landmarks.

The engineer measured the flatnesses of the metal plates to ensure they met the strict tolerance standards.

Make sure the surface is flat before assembling the model.

The old block of flats on the corner will be renovated next year.

The pianist struggled to tune the F-flats on the antique piano.

The orchestra struggled to tune the F flats before the concert.

The composer decided to replace the melodic C flats with B naturals to simplify the passage.

During the rehearsal, the pianist struggled to tune the G-flats so they matched the orchestra.

Birdwatchers gathered at the tidal flats at dawn to photograph the migratory shorebirds.