Saws and log splitters are the top causes of serious hand injuries.
In a study of two years of data, a reconstructive surgeon at Hutt Hospital, found machinery accidents resulted in more than a fifth of all hand injury admissions to hospital, ahead of sports, glass, doors and knives.
Ryan Ruxton said when people were injured by saws and log splitters, they needed more operations and spent 70 percent longer in hospital.
He said they also resulted in more reattachments than other injuries.
Dr Ruxton said the government should adopt stricter rules around the design and safety of such machinery to lower the risk of severe injury.