Robert Easton, 56, suffered broken legs and a shattered left ankle after he was struck by a one tonne mould he was turning over with an overhead crane at the facility in Denny, Stirlingshire.
As he attempted to turn one half of the mould over, it swung towards him.
Mr Easton's legs were crushed between the casting box and a cast iron platform before the mould swung away. It swung back in and struck him a second time. Each half of the mould weighed about one tonne.
The operators, Specialised Castings Limited, have pled guilty at Falkirk Sheriff Court to breaching the Health and Safety At Work Act in a prosecution brought by the Health and Safety Executive [HSE] following the incident on May 27 2011.
Mr Easton, an experienced moulder from Falkirk, had been preparing the two-part mould for use when the accident happened.
Mr Easton had metal pins and rods inserted into his legs and has also had to undergo a muscle graft and skin grafts.
The court heard that different approaches to turning the moulds were taken by various employees, and there was only one person who had actually been trained to turn them safely.
The firm had no risk assessments in place to deal with the process.