Kai Bell, 19, was arrested after being spotted in the passenger seat of a car with a balaclava on his head and a foot-long Gurkha machete in the foot well.
The Ford Mondeo was stopped in the Heath Town area of Wolverhampton with Bell and fellow gang member 24-year-old Shamar Fairclough inside on February 15.
Fairclough fled as the car was pulled over in Woden Road but Bell was arrested.
A small dagger was found discarded near the Mondeo and Bell later told detectives in an interview he used the balaclava as a hat.
Officers then managed to trace Fairclough, from Coppice Green Lane, Shifnal, and arrest him.
According to police Bell is a "prominent gang member" who uses the street name 'Muller', has previous convictions for possessing a Samurai sword and features in drill music videos where he makes veiled threats to rivals.
On Wednesday at Wolverhampton Crown Court, both Bell and Fairclough were found found guilty of possessing a bladed article.
Bell was jailed for 15 months and given an additional three months for breaching a community order.
Fairclough was jailed for nine months.
Bell, of Hopyard Gardens, Bilston, was also handed a five-year Criminal Behaviour Order banning him from:
Meeting in public with any of 14 named associates
Possessing more than one mobile phone
Inciting violence through online videos
Visiting parts of Wolverhampton
West Midlands Police Sergeant Dave Stanley, from the Wolverhampton Gangs Unit, said: “We strongly suspect Bell was on the way to commit a serious, violent offence: we found two lethal weapons and the balaclava was on the top of his head ready to be pulled down.
“It was a great spot by the officers that day and they may well have saved someone’s life or at the very least prevented a very serious injury.
“Bell is only 19 years old but seems increasingly prepared to arm himself with weapons.
"He has a previous conviction from last year of possessing a Samurai sword and there have been several tit-for-tat incidents between gangs in the city.
“This was not the case of a youth carrying a knife. This is an organised criminal carrying a weapon with the intention to use it.
“Bell had been arrested several times but, to date, we have not had enough evidence to put him behind bars.
"He’s now been jailed for 18 months and can expect to spend much of his adult life in prison unless he turns his back on gang activity.”