The two men, 37 and 40, were found guilty by Varberg District Court of kidnapping, aggravated robbery and interference in a judicial matter, Hallands Nyheter reports.
According to the court, the crimes included “elements of humiliation and, to a certain extent, sadism.”
The victim, 45, was ambushed on his farm outside Varberg early one December morning last year.
He was beaten with a baseball bat and thrown into the cellar of his house. There he was nailed to a work bench and threatened with a pistol and a gas flame.
He was later forced at needlepoint to sign his name to a document handing over ownership of his car, motorbike and lawnmower to his assailants.
Once he had completed this task, his arm was injected with an overdose of heroin.
In its judgment, the court rejected the claims of one of the convicted men that they had come into possession of the goods by legal means.
That the victim “might have cooked up his story because he regretted a voluntary sale […] is in no way probable,” said the court.