Mr Penhalagan of Bridgend suffered fatal head injuries and died later at the University Hospital of Wales, Cardiff.
A Health and Safety Executive (HSE) investigation found that, while there was no mechanical defect with the crane, the hooks were able to move at head height near to operators on the ground without adequate safeguards.
This led to HSE prosecuting Celsa Manufacturing (UK) of Castle Works, East Moors Road, Cardiff. The company pleaded guilty to breaching section 2(1) of the Health and Safety at Work etc Act 1974 at Cardiff Crown Court. It was fined £200,000 and ordered to pay costs of £36,294.38.
After sentencing, HSE inspector Stephen Jones said: "This was a horrific incident - an extremely heavy, moving piece of equipment was able to strike Mr Penghalagan directly in the head because Celsa Manufacturing didn't have safe systems of work in place."
"The operation had recently moved to a new melt shop but while there was no mechanical defect with the crane, the company did not address the fact that the hooks were able to move at head height near to operators on the ground.
"The system of work did not enable crane operators at the site to clearly see employees working on the ground, putting them at serious risk of being struck by moving objects.
"Celsa should have put in place a thorough risk assessment and most importantly acted upon that assessment, given the generally hazardous nature of this type of operation - but sadly the plans in place were just not adequate and led to this man's terrible death."