Twenty-year-old Heardman will stay with the League Two side until January 2017, and could make his debut for Craig Hignett’s men in their Checkatrade Trophy tie at Notts County on Wednesday night.
The tall frontman started this season in the Magpies’ Under-23 side, returning from long-term injury to start his first game in over a year in Peter Beardsley’s side’s pre-season friendly at Ashington earlier this month.
Gosforth-born Heardman netted his first goal since his comeback against Barnsley in another friendly, before scoring in United’s second string’s 3-1 Premier League 2 defeat at West Ham last week.
He also spent time on loan at National League side Gateshead in 2014, and could now make his Football League bow for Pools at Notts County on Saturday.