Police are to use hundreds of airport-style and hand-held weapon detectors in the crackdown on knife crime.
Teams of 15 officers will be deployed across the 10 boroughs in London that have recorded the most knife crime.
Assistant Commissioner Tim Godwin, head of territorial policing in the capital, said officers would be deployed in areas blighted by stabbings to stop and search teenagers suspected of carrying weapons.
Police admit the “in your face policing” is expected to raise community tensions in some areas.
But they say they are getting significant support from communities desperate for them to crack down on the problem.
Officers will use contentious Section 60 powers to enforce effective “no-go” areas for people carrying knives.
The powers enable officers to stop people and search them without the need to have “reasonable suspicion” that they are engaged in wrong doing.