Latrave Ltd of Wellingborough appearing before Wellingborough magistrates (May 16) admitted breaching the Health and Safety at Work Act.
The court was told that the injuries to the hand of the 19 year old agency worker in August 2010 were so severe that he had to have part of his thumb amputated.
Evidence was given that the employee was being trained to fix a problem on a running printing press when his left hand was pulled in between two rollers.
When the HSE began to probe the incident it was discovered that the correct guard was not on the machine and that the worker was not being trained in the correct manner.
The company was fined £8,000 with £14,700 costs.
Following the case a spokesman for the HSE said: "This inexperienced 19-year-old agency worker has suffered serious, permanent harm because Latrave Ltd failed to ensure his safety when operating this machine. His future career path may have been changed and it will have a lasting effect on his life.
"The machine had guards missing, he was shown dangerous practices like keeping it running while fixing it, and was not properly supervised for someone who had only worked for the company for less than three weeks.
"Companies need to make sure all guards are in place on their machines no matter who is using them, but inexperienced workers need greater training and supervision because of their lack of experience. HSE will inevitably take action against firms who fail in these ways."
