Rotherham mechanical seal maker AES Engineering saw its profits hit £18.3m on £146.5m sales in 2013. Chris Rea bought the company in 1979 and turned it round. AES makes mechanical seals to stop leakage of harmful liquids and gases into the environment, selling to a range of sectors including refining, pharmaceutical, chemicals and power generation.
Latest turnover: £146m
Five-year rise in turnover: 74%
No. of employees: 1668
Five-year rise in employment: 38%