Leon Glasgow, 37, from Ipswich, attempted to rob a G4 security van, which was parked at The Peel Centre in Skimped Hill Lane between 4-4.15pm on August 30 last year.
Two G4 security guards were replenishing a cash machine when Glasgow attacked one of the guards, wrestling him to the ground.
However, he was unable to obtain the cash and fled the scene empty-handed.
The security guard sustained cuts and bruises during the incident.
He pleaded guilty to one count of attempted robbery and one count of failing to provide security code contrary to RIPA at Reading Crown Court yesterday.
He was arrested on suspicion of attempted robbery on September 2 last year and charged on March 4.
The second offence relates to Glasgow refusing to provide police officers with the password to his phone, which had been seized by police.
He was sentenced to seven and a half years’ imprisonment for the attempted robbery and one year in prison for failing to provide security code contrary to RIPA. The two sentences will run concurrently.
Investigating officer, Det Con Ross Fleming of Force CID said: “I welcome the sentence imposed upon Glasgow, who caused both physical and psychological injuries to one of the G4 security guards. I am also glad that the judge took into account the victim’s impact statement before sentencing Glasgow.
“I would like to thank the members of the public who assisted in the investigation, as well as colleagues at Suffolk Police who arrested Glasgow and helped with the investigation.
“Residents are certainly safer now Glasgow is behind bars."