Stephen Cannon, 39, made an arsenal of incendiary devices from fireworks and potassium carbonate.
He filmed himself blowing the bombs up in woods to test their effectiveness.
He earlier pleaded guilty to making the devices on numerous occasions between 27 April and 5 June last year.
Livingston Sheriff Court was told he planned to target West Lothian firm, Ruskim Seafoods, because one of his friends had a job dispute with the company's bosses.
The court was told he taught his friends how to make and ignite the firebombs which he planned to use against employees of the firm.
Police said his campaign was uncovered after five homemade incendiary devices were found under a car parked in Dechmont, West Lothian.
It is understood the car belonged to an employee of the Livingston-based fish company.
The discovery sparked panic and led to the village's Main Street being evacuated and the main road closed for two hours.
Police acting on information called in the bomb squad before raiding Cannon's council house home in Armadale, West Lothian, on Tuesday 14 June 2016.
They discovered a stash of "potentially explosive and flammable materials" in the flat and arrested Cannon and his two flatmates.
Rebecca Swayles, prosecuting, said Cannon's targets were all employees of Ruskim Seafoods.
Cannon and his flatmate Stuart Clark, 22, earlier had not guilty pleas accepted to culpably and recklessly putting five "hydrogen bombs" under a car in Dechmont, West Lothian, on 6 June last year.
The charge alleged they knew the bottles filled with potassium carbonate and aluminium foil would explode, damaging the Mazda 6TS and placing members off the public living nearby in danger.
Another flatmate, 19-year-old John Clark, had a not guilty plea accepted to placing Michael York, a sales director at Ruskim Seafoods, in a state of fear and alarm for his safety.
He denied making threatening and menacing comments to Mr York in an earlier incident on 31 March 2016.
Det Insp Steven Bertram, of Police Scotland, described Cannon's actions as "reckless and dangerous".
He added: "These devices could easily have caused burns or other injuries.
"Cannon's conviction should serve as a warning that this sort of behaviour will not be tolerated by Police Scotland."
A bomb maker has been jailed for 21-and-a-half months for turning his West Lothian flat into an explosives factory in a feud against a fish company which employed his friend.