Eddie Ely, a chargehand at Forterra Building Products, and a group of coworkers were cleaning a conveyor when the accident happened on 8 July 2017.
The conveyor's guards had been taken off to help remove a blockage, but the electrical power supply had not been isolated, Burnley Magistrates' Court was told.
Forterra was fined £200,000 and ordered to pay £7,530 costs after it admitted breaching s 2(1) of the Health and Safety at Work Act.
The Health and Safety Executive (HSE) found that the company did not ensure that machines were always isolated from power before guarding was removed.
In its latest full-year accounts, filed with Companies House, Forterra said: "Our progress on health and safety during the year was overshadowed by a serious accident suffered by one of our employees at a brick manufacturing facility."
The company operates 18 factories in the UK, including nine brick manufacturing facilities, and two sites producing aggregate and aircrete blocks. It reported a turnover of £331m for 2017.
HSE inspector Steven Boyd said: "It is crucial companies have a clear procedure for isolating machinery and they have appropriate supervision and monitoring to ensure it is adhered to."
