Image shows the murderer Blaise Lewinson.
Blaise Lewinson stabbed Stefan Appleton, 17, with the 25in (63cm) serrated blade in the leg and chest last year in a north London park.
Lewinson can be named after Judge Richard Hone QC lifted reporting restrictions, saying he should be identified as a deterrent to others and because of the public interest.
A jury deliberated for 14 and a half hours to convict the 17-year-old defendant of manslaughter but clear him of murder.
Sentencing Lewinson, who appeared in court at the Old Bailey in a white shirt and tie, Judge Hone said he regarded the killing as “very close to murder”.
He told him: “You were in the middle of your GCSE examinations but you preferred to commit serious knife crime in a busy London park filled with young families.”
The judge called him a “dangerous offender” who had a “fascination with illegal knives”, and said he had shown “no true remorse”.
Image shows the zombie killer machete.
He said: “The use of this utterly ferocious weapon, even with the reduced intent, caused the loss of Stefan Appleton’s young life.
“He plainly was unarmed and you stabbed him on the ground while he was defending himself.”
Judge Hone added: “What you did that evening and in the aftermath, coupled with your history of previous offending and non-compliance with court orders, justifies my conclusion that this is one of those rare cases where the court should pass a discretionary life sentence.”
Lewinson was told he must serve a minimum of nine years before he can be considered for release on licence.