It happened on West 40th Street and Eighth Avenue around noon, when police say 54-year-old Wayne Welds approached the family and swung the pipe.
The victim was struck in the head and suffered a laceration.
ALSO READ | Off-duty police officer fires shot during dispute over fireworks in Brooklyn
Authorities say Welds then threatened the rest of the family with the pipe still in his hands.
He then fled the scene and was apprehended a short time later.
The victim was taken to Bellevue Hospital in stable condition.
Welds is charged with assault, criminal possession of a weapon, and menacing.
ALSO READ | With new COVID-19 delta variant spreading, communities scramble to vaccinate
* Get Eyewitness News Delivered
* More Manhattan news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube
Submit a News Tip