College students said they felt safer for having a walk-through metal detector on campus after a lockdown earlier this month following a knife incident.
Milton Keynes College started trialling the knife arch in October.
The college acquired a second machine after positive feedback from both parents and students.
The decision followed the college being advised to lock down by police amid a nearby knife incident on 9 November.
Ahmednur Nuur, 16, also died on 16 February 2022 outside the college after being stabbed in the back by Justice Will-Mamah, 19. who was jailed.
A survey carried out by the Safer MK community safety partnership found 86% of students "feel safe" thanks to the presence of the airport-style arches.
