Moped-riding Nizar Msaad, 22, and Shaquille Allen, 26, tried to grab five of the luxury watches worth tens of thousands of pounds.
They managed to snatch two during a 90-minute spree in London’s Mayfair, Soho and Hoxton in 2022.
The pair punched, kicked and threatened the victims with machetes.
A specialist Met Police team targeting moped crime traced their route on CCTV and identified them when they took off their crash helmets.
DNA belonging to both was found on the moped.
Msaad, of Southgate, North London, and Allen, of no fixed address, both admitted robbery.
Detective Constable Mike Bagnall from Operation Venice, said: “These were violent attacks on innocent people in the middle of the street in central London.
“It was just fortunate that no one was seriously injured during these reckless offences.
“The investigation was thorough and detailed and we were able to trace the Msaad and Allen and build an overwhelming case against them.
“These were violent robberies and I am glad our determination to find those responsible enabled us to take both these men off the streets.”
This week they each got three years and four months in jail at Wood Green crown court.