A teenage apprentice is said to have escaped serious injury thanks to the thermal underwear he was wearing.
Trainee joiner Owain Bancroft, 16, from Swansea, was taken to Morriston Hospital's A&E department after an industrial sander caught on his thigh.
His flesh was trapped in the machine but the extra layer of clothing was also caught, reducing his injury.
His mother, Lisa Bancroft, who bought her son the underwear, said: "Owain was extremely lucky."
She added: "It was miraculous that he didn't get a very serious injury.
Owain's father, Paul, is a cabinet maker and was able to show medical staff an example of the sander and how to take it apart.
Mrs Bancroft said: "My husband took an identical sander into the A&E department and demonstrated how it was dismantled so they were able to remove it from Owain's leg."
The sander was removed after Owain was given an anaethetic. The teenager did not need surgery.
A hospital spokeswoman siad Morriston A&E staff deal with injuries caused by machinery or equipment, which also have to be removed, about twice a year.